Are a little bit talking about the macro environment we find ourselves in. Quite often, as we see more generalist investors come into the space, where to from here for gold? We have seen interest rates start to increase, particularly long-dated treasuries, but I would argue that's really a symptom of underlying increasing inflation, which is actually infecting the supply chains for many of the operating companies. I do think it bears repeating that the royalty model in this point of the cycle is superior to producers. Producers are, of course, facing significant reserve constraints. They're cannibalizing each other to replace depleting production levels. They're not really providing a leverage proposition that investors are looking for because their share count is increasing while their production and reserve profiles are effectively static.
The other thing that we're seeing is, of course, significant cost pressure, particularly in the last several months when we've seen a big increase in oil prices, which has infected the supply chain really across all inputs within operating companies and at the mine site. Also on a lagging basis, given that we've seen record metal prices across the entire metals complex, not just in gold, but we're seeing in copper and other metals, we're going to see a lagging impact on labor costs. We're seeing much more strike action in terms of the collective bargaining process in a lot of operations, whether it's base metal or precious metal. Inevitably, that will lead to cost inflation. When you look at costs at the mine site, the majority of costs are coming from labor and energy.
Of course, we've seen significant inflation in energy costs in the last several months, and that, coupled with cost inflation, which labor will deliver over the coming year or two, will result in significant cost inflation and erosion in the multiple and margin expansion that you're looking for from operating companies. They're not going to be providing the leverage proposition that investors are looking for as gold prices increase over the next little while. Gold prices will continue to increase because, as I said, the underlying factors that are driving the gold price higher, which is the debasement of fiat currencies, is not going away. As I said, real interest rates are effectively flat or declining because even though nominal rates are going up, inflation is accelerating at an increasing rate, and that will continue to drive capital into the sector.
Clearly, fiat currencies are being debased. We're seeing money supply continue to increase on an exponential basis, and that's really been the value proposition of gold over the last several years that's driven it to this all-time highs. I think really the question you have to ask yourself when you're investing in the gold sector as a generalist is where are you going to get optimum leverage through the gold price and leverage the exploration success of the underlying operators in which we own royalties. That's provided in the royalty model in which we think is going to really deliver outsized returns in a rising gold price environment with significant underlying inflation in the sector. Where does Gold Royalty fit in that type of context? We are providing peer-leading growth in the sector.
A six-fold increase or about a 500% increase over the next four years in our underlying gold equivalent production from assets that are effectively built and ramping up. Very low construction risk. We have over 260 royalties. Certainly, we have a lot of early-stage optionality with 10 royalties that are already cash flowing, and by the end of the decade, 20 within our portfolio delivering that cash flow in gold equivalent production growth. We are providing low risk in low-risk jurisdictions growth within the sector with unmitigated leverage of the gold price because all of our royalties are completely bought and paid for. We don't have to put another dime into them to deliver that peer-leading growth, which I'll get into in a little bit more detail over the course of the presentation.
The other thing that I would point out is we've never been healthier from a balance sheet perspective. We're completely debt free. We are and have been generating free cash flow for the last two years, and that cash flow will increase exponentially over the next several years as we deliver that peer-leading growth. With a $150 million line of credit available, completely available, $50 million of cash on the balance sheet on a pro forma basis with our in-the-money warrants, which will be maturing over the coming months. We have about $200 million of dry powder to continue to invest in new growth opportunities, which will deliver accretion on a cash flow per share basis because we don't have to go back to the equity markets to do acquisitions given the scale of our balance sheet currently.
This gives you a historical perspective of how we've grown out the portfolio, and it's important to point out that we do have multiple platforms for growth. We've gone from a standing start a little over five years ago, no revenue, 18 royalties, almost exclusively on the portfolio of our former parent company, GoldMining Inc. Through a succession of acquisitions, roll-ups over the course of 2021 of three of our peers that delivered 150 additional royalties and vastly diversified our portfolio. We've been systematically using the treasury from our IPO to pick up individual royalty acquisitions that deliver cash flow per share accretion in the immediate term to supplement the significant optionality and growth we already had embedded in our portfolio. Today, we stand at over 260 royalties, and again, all of those royalties are completely bought and paid for. We have no capital calls.
We have no installment payments. We have no step downs. We really have unmitigated growth in our portfolio over the next several years. Again, really what's delivered that growth is the fact that we have diversity in terms of how we grow. We have four distinct platforms of growth, and clearly when we had the multiple to do so, we used the arbitrage available to us back in 2021 to vastly diverse our portfolio through the roll-up of three of our peer companies. We used the M&A when we had the currency to do so. We haven't had the currency since then. As a result, we've been extremely disciplined and focused on cash flowing and near cash flowing royalties that we could use our treasury on to deliver cash flow and net asset value per share accretion in the short term.
We are disciplined in terms of focusing on distinct aspects of our platforms for growth to deliver growth when we have the ability to do so. In the last several years, we have been focusing on individual royalty acquisitions, third-party royalty acquisitions, and also done some project financing, as we did with Eco Oro Minerals Borborema Mine, quite successfully to deliver significant cash flow growth in the short term. Having those four distinct platforms for growth has been very important. The other element of it is, yes, we are doing early-stage royalty acquisitions, but we are doing it at no cost to our shareholders because we have a royalty generator model where we stake exploration claims around existing mines and deposits. We farm those properties out to our neighbors, take royalties back in return at no entry cost for our shareholders.
The prospect for infinite rates of return is really what those early-stage options deliver, recognizing that they have a low success ratio, which is why we do not want to expend precious treasury in order to add those early-stage royalties into the portfolio. Where that leaves us today in terms of our portfolio in terms of metal exposure, it is over 90% gold in terms of the net asset value of our underlying portfolio. Interestingly, in the short term, because of the Vares acquisition, Pedra Branca, and the Cozamin royalties, about 30% of our revenue in the short term is actually coming from copper, which is obviously experiencing all-time highs.
We have significant leverage to the copper price in the next couple of years while we are waiting for some of our significant royalties on the gold side to kick in significant growth over the next several years, namely from Odyssey, the underground extension of Canadian Malartic, Ren, the underground extension of Gold Strike, and Côté, which is now ramping up to expanded production over the course of the next several years. The other thing I would point out is we have the lowest political risk exposure within our portfolio across the entire royalty universe, with over 80% of our royalty portfolio by number and value focused on Nevada, Quebec, and Ontario, which perennially is rated among the five best jurisdictions in which to operate for mineral potential, low political risk, and low regulatory risk by the Fraser Institute in Canada.
Peer-leading growth, certainly up among the leaders this year, over 60% growth in gold equivalent ounces this year alone. Just in the first half of this year, we saw a doubling of our revenue in the first six months relative to where we were last year. That growth is happening in real time. We are in escape velocity right now. We are generating strong free cash flow. That treasury balance is growing quarter in, quarter out from this portfolio that we have been meaningfully investing in over the last several years. We are getting that significant return on that capital investment that we have been making systematically since our inception in 2021.
What that means over the next several years is 500% growth in gold equivalent ounces. That is a sixfold increase in our gold equivalent production over the next several years from some of the biggest mines within North America.
I would hasten to add that growth is coming from assets that are effectively built out. 70% of our growth is coming from assets that are already constructed. Another 20% of that growth is coming from satellite deposits to existing mines. In other words, the infrastructure is already in place and those satellite deposits are systematically being incorporated into the mine plan of those mines. That is delivering that sixfold or 500% growth in gold equivalent ounces over the next little while. So very low risk from many of the best capitalized operators in the sector. When you look at our gold equivalent ounces on a consensus basis, not that different than what we had in terms of our internal estimates and the guidance we provided on a one-year and five-year basis.
You can see that by the end of the decade, we are approaching 30,000 gold equivalent ounces of production. When you layer on various gold price assumptions on top of that, you are looking at at least $150 million of revenue by the end of the decade against $7 million-$8 million at cash G&A. A very scalable business, which means that we are going to be generating sustainably over $100 million of free after-tax cash flow per annum by the end of the decade from an existing portfolio that is completely bought and paid for. That portfolio is not underpinned by a collection of small-scale assets.
We have royalties on three of the five biggest producing gold mines in North America, namely Canadian Malartic in the underground extension, Odyssey in particular, the underground extension of Gold Strike, Ren, which is coming into production in the next several months, and also Côté, which is one of Canada's biggest producing gold mines. We have seen some significant ownership shifts in some of our existing mature portfolio of royalties, which has allowed those operations to be recapitalized, extended in mine life, namely Discovery Silver taking over the assets in Porcupine District from Newmont, where we have a royalty on the Borden satellite deposit, which has been in production for about half a dozen years.
We have seen Discovery meaningfully invest in brownfield exploration and expansion opportunities at that asset in particular with Adriatic Metals selling to DPM, the Vares operation, and that is ramping up meaningfully and DPM is looking for opportunities for expansion as well and extension of what is already an 18-year mine life on a meaningful copper stream that we have in that operation in Bosnia. Pedra Branca recently changed ownership from BHP to CoreX. Again, a recurring theme, CoreX is investing meaningfully in the capital infrastructure in that mine and brownfield expansion as they invested over $500 million in the acquisition of that opportunity. That means that we are going to see a recapitalized mine delivering that optionality to our portfolio at no cost to us. Again, all of our royalties are bought and paid for.
We don't have to contribute to any of these expansions or exploration that's being conducted on these underlying assets. When you look at our pipeline, it's immense, and this does not capture all 260 royalties. This captures a small subset of them. As you can see, we have about 10 cash-flowing royalties, another 10 that are in various stages of construction and development. Most of that construction development is behind us. These are assets in ramp-up. You're going to see effectively a doubling of our cash flow royalties over the next several years, underpinning that sixfold increase in our gold equivalent ounces. We have meaningful optionality in the portfolio, early-stage opportunities, virtually all of which we generated organically at no cost to our shareholders. Again, we generate these royalties through our royalty generator model.
A full third of our royalty portfolio were generated organically at no cost to our shareholders. That provides significant optionality, and a great way to quantify that optionality is how much exploration activity is occurring at the mine site. Those mines are actually investing about $200 million per annum in exploration, at least 500,000- 600,000 m of diamond drilling each and every year. We're contributing absolutely nothing to those exploration budgets, but we're getting the full benefit of the exploration success of our underlying operators. I think that's a meaningful opportunity for our shareholders to capture exploration optionality at no cost, no dilution to our shareholders, which I think is an important element of any royalty story. It's certainly not unique. That's the royalty model.
What we try to do in this presentation is quantify what that means in terms of dollars spent and meters drilled on these properties. You saw Brett very capably explain the multiple disparity in the space, and I think these numbers are by and large in line. These are consensus estimates of pricing that asset value. Certainly at the high end of the food chain, what that tells you is that critical mass does matter. Having that critical mass means they could sustainably get multiples on a P/NAV basis of between two to three times. That allows them to perpetuate their business because the arbitrage is available to them. When you look at the smaller end of the food chain, what it does tell you is much higher multiples are afforded to companies that have meaningful cash flow in the short term.
Where we're at that point now, where we've inflected last year into positive free cash flows, we think the re-rate potential is immense. We're creating critical mass organically from the existing portfolio. We're going from about 7,000, 8,000 gold equivalent ounces of production this year to 30,000 gold equivalent ounces in the next several years from some of the largest producing gold mines in North America that are already well capitalized, well-financed, and really ramping up to full production over the next several years. We do believe the re-rate potential within our portfolio is immense without having to put any more capital to work. Again, with the balance sheet that we have, no debt on the balance sheet, $150 million line of credit, $50 million of cash on a pro forma basis, including the in-the-money warrants.
We certainly have a lot of capital to focus on new royalty opportunities that add accretion to cash flow per share in the short term with no risk of dilution to our shareholders as we now are meaningfully into free cash flow, over the next several years, only growing exponentially from the existing portfolio of royalties. The portfolio of companies or investors has certainly transformed over the last several years, much like Metalla. As Brett said, we have gone from a largely retail-driven story in our IPO to one that is well owned institutionally. Tether has become a meaningful shareholder, as it has for a number of peers within our space. I welcome that because generalist type of capital is really important in terms of driving multiple expansions in the sector. We see Tether as a proxy for the generalists.
The type of investors that invest in the stablecoin universe are not traditional gold investors. We are capturing a new class of investors, a younger demographic that historically really has not looked at gold, and Tether has obviously made a very strong macro call of rotating into physical gold and to equity, and royalties companies in particular, that offer meaningful and superior leverage to the gold price. Well covered on the sell side with about seven analysts covering us with an average target price over $5 per share. Again, just to emphasize what we have been able to build over the last five years, tier one assets in tier one jurisdictions with meaningful growth, sixfold growth in our gold equivalent ounces from the existing portfolio that is largely built out.
90% of it is effectively built or satellite deposits within brownfield, and well-capitalized industrial infrastructure to deliver what we said is peer-leading growth over the next five years from the existing portfolio. With that, Eric, I will maybe leave a couple of moments for questions.
Excellent. Thank you very much, David. I really appreciate that. Excellent update, too. Do we have any questions from the audience? Maybe just a question from my side, David. In terms of the portfolio, obviously, lots of great assets run by skilled operators. What asset or maybe assets do you think maybe the investors do not fully appreciate the potential for upside there?
Well, I'll give you an example of the potential rate of return, growth that we could deliver from our royalty generator model. I would say, for example, Tonopah West, which is owned by Blackrock Silver. We actually staked that property back in 2021 at no cost to our shareholders. We sold it to Blackrock Silver back in 2024 for about $1.5 million in cash and a 3% NSR on the property. It has the potential to be in production by the end of the decade. So zero entry cost, infinite rates of return. I can tell you that our vast pipeline of early-stage royalty opportunities deliver that type of infinite rate of return potential, and there's no holding costs associated with any of them. So we can afford to wait, be patient, and wait for those projects to be brought into production.
But you're correct. I mean, those are the opportunities that really are not recognized, not afforded any value in the marketplace, but have the potential to deliver outsized returns in a very short period of time, particularly in the hands of some skilled operators with well-capitalized balance sheets.
All right. Fantastic. I think we're out of time for now, but, really appreciate the update and thank you very much for your presentation.
Thank you.