Forum Americas. Today is an exciting day for Vox. We just announced the new silver royalty acquisition in Australia that I'll touch on a bit later. In the last month alone, we've announced three separate transactions to acquire royalties in Australia. You're hearing us at a really exciting time in our growth and at a period where we're delivering exponential revenue growth as well. A lot of exciting things to touch on. I will be making some forward-looking statements, so I'd refer you to the disclaimer in our corporate presentation on our website. Vox at a snapshot. Vox was created 12 years ago, so we've been through multiple cycles and seen the royalty sector evolve.
As a company, our focus is on finding overlooked or hidden value in legacy royalties that are typically 20- 30 years old, that cover ore bodies and projects that are on the cusp of construction and production. Typically, we're buying royalties from eclectic third parties like hearing aid technology companies, ranches in Nevada, automotive parts companies at deep discounts to their NPV, and then waiting a space of one to three years until they come into production. Our revenue is approximately $35 million based on current- year guidance. In addition to strong revenue, we also offer a lot of ounces in the ground. Our royalties and streams cover circa 1 million gold equivalent ounces in the ground. There's a lot of medium to long-term blue sky there as well. We have over 80 royalties and streams in the portfolio today.
You'll hear me talk like a broken record about returns. We're not trying to run the world's biggest royalty company. We're not trying to arbitrarily goal seek our revenue up and to the right. We're focused on return on capital and per share returns. This year, we expect to generate 28% return on invested capital, which is the highest return on capital in our entire royalty industry. A little bit about our capital structure and our portfolio. We're about a $400 million U.S. market cap. Net cash of $31 million. No debt, but we've got a credit facility that's fully undrawn of $75 million. Our share register includes some of the who's who of mining funds and a very strong U.S. generalist investor audience as well.
We're lucky enough to be on the Russell 2000 Small- Cap Index in the U.S. through our Nasdaq listing, and also recently joined the GDXJ. We were the first royalty company to be both on the Russell 2000 and GDXJ. A little bit about our asset portfolio. As I mentioned, we have over 80 royalties and streams. We're principally gold weighted. Circa 90% of the portfolio is gold and the balance is largely copper. We're heavily weighted towards Australia. About 70% of our portfolio is weighted towards Australia. We think it's the world's best mining jurisdiction, particularly in terms of timelines for permitting and to take a new discovery through development into production. We have 11 of our 83 royalties are producing today, and we expect that to organically grow to over 20 in the next two to three years. A little bit about our revenue growth.
As I mentioned from the outset, we really have been on an exponential sort of revenue growth sort of journey. Last year, we generated approximately 50% revenue growth to $16.6 million. This year, we expect to basically increase that by 100%. The midpoint of guidance is about $34.5 million. In May of this year, we did an Investor Day, and for the first time ever, we disclosed 2030 expected guidance and outlook for potential revenue of between $66 million- $100 million. That's with no additional acquisitions. That doesn't even include today's acquisition of that silver royalty. You're hearing the Vox story at a really exciting time in terms of recent acquisitions and very strong momentum in our revenue growth. Our whole team is a team of seven professionals.
G&A historically over the last four years, we've held that very constant, even reduced it between $5 million- $6 million. Given our effective tax rate is about 7%, largely because of our streams, we offer very high sort of operating cash flow per share growth in addition to top-line revenue growth. I mentioned that we're obsessive about returns. On the left chart, you'll see what we've delivered on return on invested capital. For the last five years, we've generated between 20%- 27% annual return on invested capital. This is really what excites us. Finding these overlooked legacy royalty contracts, acquiring them at great value, and then harvesting the cash flows for the benefit of our investors.
We've had plenty of opportunities to bulk the company and to grow to $1 billion through some of the numerous auctions that are in the market, but that isn't success for us. Success for us is compounding per share returns and consistently generating the highest return on invested capital in our industry. If you look at the middle chart, cash flow per share has also grown exponentially at a CAGR of 76% over the past four years. We're trying to minimize dilution while we continue this top-line revenue and free cash flow growth, obviously. We deliver this through building in a very healthy margin of safety into our acquisitions. We focus on very simple ore bodies, shallow open pit gold in Western Australia.
If we see a technical mining risk that our in-house team of mining engineers and geologists can't price, if it's too deep, if the flow sheet's too convoluted, if you need five different metals to be recovered to make the economics work, we'll just say no. Part of what makes us able to say no to so many opportunities is, over the last 10 years, we've built the world's largest proprietary database of royalties. That database numbers almost 9,000 separate royalties. Fundamentally, we're not opportunity constrained, we're returns constrained. If we don't like the returns on a certain asset or a certain deal, we'll happily say no and move on to the next opportunity. That's what has allowed us to generate 20%- 28% return on invested capital. As I mentioned, we just announced a new royalty acquisition today.
We announced we're acquiring an uncapped silver royalty in Australia, in Western Australia, that's in construction at the moment, called Sorby Hills. This is a really exciting asset. As many of you would probably know, Australia doesn't actually produce a lot of silver compared to parts of Mexico and the Americas more broadly. It's pretty rare to be able to get producing or construction- stage silver exposure in Australia, particularly at a discount to NAV. We're really excited to announce this transaction today. First production is expected in the second half of next year, so we're within 12-18 months of first production, which is really our sweet spot. Another attribute that really excited us about the Sorby Hills asset, is if you look at the actual current resource to reserve conversion, less than 40% of the resource is currently sitting in reserves.
The operator, Boab, has been doing an extensive drill program recently, and they're expecting to increase the reserve upgrade, to release a reserve upgrade later this quarter. We think this asset has potential to have a mine life between 10-20 years just based on the existing resource base that's already been delineated. A really exciting asset that we're acquiring for $13 million that we announced today. I mentioned this is the third deal we've announced in the past month. We've just closed two other deals in Australia in the last two weeks. It was to acquire these three royalties, principally gold and copper royalties that cover over 2,000 sq km in Australia. It's actually an interesting pairing of assets. It's two deals to acquire three separate royalties.
It includes a producing gold royalty called White Dam, a development stage copper- gold royalty in Queensland called Kalman, and a very large exploration stage royalty in Western Australia operated by Capricorn Metals called Sylvania. With White Dam, what we really liked about that asset was there's been a recent copper-gold discovery. The heap leach is currently producing, but we effectively get this copper-gold discovery for free. Kalman, what excited us about this was that the Mount Isa region in Queensland is actively being consolidated, and this is a large 40- million ton resource that has very attractive copper-gold and moly grades, that is subject to a takeover from an adjacent operator called Austral Gold. They're expected to close that acquisition in November of this year. They've flagged that Kalman's a near-term feed source for their 3- million ton Rocklands mill.
This is an asset that we looked at a couple of years ago, was a little bit sleepy three years ago, but with the consolidation of the Mount Isa region in Queensland, we're really excited about the near-term prospects for Kalman to be fast-tracked into development and production through the adjacent Rocklands mill. Sylvania, this is an exploration royalty, essentially gave us three shots on gold. It's a gold exploration royalty operated by a $7 billion Aussie producer over 1,700 sq km . Secondly, it also contains a 1.4- billion ton iron ore deposit with a historical scoping study on it to produce 5 million tons of iron ore. Thirdly, it also contains the Prairie Downs silver- lead- zinc deposit that was also subject to a 2008 feasibility study.
Essentially we get one feasibility stage base metal deposit, a scoping stage, very large iron ore deposit, and an exploration royalty, all for circa less than $1 million on that Sylvania royalty. A very exciting portfolio of assets cobbled together from two separate acquisition transactions. You're probably going blind looking at this slide because there's so much detail. Don't worry. You don't need to go through every line by line. This just shows a subset, about half of our portfolio of 83 royalties and streams, based on stage of development. As I mentioned from the outset, what really excites us is acquiring royalties and streams that are on the cusp of construction and production. What you see here is a lot of assets that we've acquired in the last couple of years that are on the precipice of construction and production.
That's where we find the deepest value in these forgotten secondary royalty contracts. A large amount of catalysts and assets that have been fast-tracked into production. By the end of 2028, we expect organically, there's strong potential to go from 11 producing assets today to over 20 producing assets. That's with no incremental acquisitions. A lot of near-term development and catalysts that we expect to contribute to near-term revenue growth. The second key point I wanted to highlight here is the preponderance of Australian flags. As I mentioned, we're 70% weighted towards Australia. Australia has been an extremely fertile hunting ground for us acquiring legacy royalties. The timelines from exploration development into production are the shortest in the world. We've seen numerous ore bodies fast-tracked within three to five years.
The quality of the geology and the kicker is the lack of other royalty companies down in Australia have meant that we've been able to acquire these assets over the past six years, at deep discounts to NAV. We're seeing some of the majors like Wheaton and Franco start to enter Australia, at implied IRRs of 2%-4%. We're really excited because we've built this portfolio over the last six years with very little, if any, competition, and we're excited to see the revenue growth at much higher rates of return from this portfolio. I think those are the main points to cover. Even if we do no further acquisitions, even if the gold price contracted by 20%-30%, we still expect meaningful revenue growth, largely as a function of new mines coming into production and top-line through volume-linked growth.
Investors in Vox are getting a really attractive portfolio that has considerable embedded growth, largely through new mines and new assets coming into production. This is a snapshot about some of our 11 producing assets. A few names that'd be very familiar here, like Greenstone, Bonikro. There's been a number of really exciting catalysts in our portfolio recently. One good example is Bonikro, our gold offtake stream there. The reserve life has increased, and the mine life has increased 300% in the space of the last six to nine months. That asset in particular, has gone from four years of mine life to 13 years of mine life, with potential beyond that. A really attractive, diversified portfolio of gold, silver, and copper royalties, with meaningful brownfields expansion upside.
I won't go into too much detail here, but we have a number of large development assets, multimillion-ounce deposits, that we expect to enter development and production in the coming quarters. I touched on some of these assets already. I guess another two other assets that I haven't touched on, Los Filos with Equinox Gold. We have a gold offtake stream on that asset, so we're excited to see the restart plan when Equinox releases that in the coming months. That's going to be a meaningful revenue and margin contributor for Vox. Likewise, Sugar Zone, they've recommenced underground development in Ontario, Vault Minerals has, and they're expecting to recommence processing of ore November of next year. A number of assets that are de-risked that we expect meaningful volume and revenue growth from within the coming quarters. A little bit about where we trade relative to peers.
This is just market cap to 2026 revenue and then market cap to 2030 revenue. We're currently trading at between 10x and 11x revenue on current- year revenue. Look, we think there's a persistent discount in the stock for a few different reasons. I think one reason, maybe me being biased as an Aussie, is that a lot of our Australian assets aren't well understood by the Street up here in North America. Savvy analysts such as Eric, who are time poor, they don't want to value 80 separate royalties and streams, which we totally understand. Most of the five analysts that cover our stock, they get to a buy recommendation on our top 20 assets. For a lot of our Australian assets, there's a lagged approach where they won't go in the DCF until the assets are either in construction or production.
We think this creates a real opportunity for investors. With the returns that we've generated and the returns we expect to generate, we think trading at the lowest end of revenue and cash flow multiples of our peers is not justified. When you project that into 2030 with the $66 million revenue number that I mentioned earlier, plus the Red Hill asset on top of that, we're trading at somewhere between 4x-6x revenue, which we think is highly unjustified. That's the job for us as management to try and educate the Street about particularly a lot of our development assets that haven't been in people's models. We're excited to be here today to help try and close part of this valuation gap. In closing, why is now a great time to be listening to the Vox story?
This year, we expect to double revenue. Last year, we increased revenue by 50%. Triple-digit revenue growth expected this year between last year and 2030. Going from $16.6 million to $66 million revenue. Over 300% organic revenue growth without any incremental acquisitions. As I mentioned, we're obsessive about return on invested capital. To be expecting to generate 28% return on invested capital this year, which is in stark contrast to most other royalty companies that are generating sub 10% return on invested capital, we think it's a really compelling story for investors, particularly generalist investors. We do pay a dividend. We've grown the dividend at 10% year-on-year for the past four years. I mentioned our embedded organic growth. I mentioned that we're trading at a significant discount to peers. Management and the Board owns over 10% of the company.
This is the majority of our personal wealth. I've got four brothers and sisters that own Vox stock, so anytime the share price goes down, I'm getting multiple phone calls from siblings. Take that with a grain of salt. But thanks for your time. Really grateful to be here today and to share a bit more about the Vox story. We've got, I think, one minute if anyone's had enough coffee to ask a question.
Thank you very much. Do we have any questions from the audience? Maybe just from my side, if you don't mind. Obviously, a big Australia focus going forward. Where do you see the makeup of the portfolio in terms of new royalties, in terms of jurisdiction, and maybe also asset mix?
Yeah. Thanks, Eric. I think we'll continue to be dominant Australian-weighted. It's where we continue to find the deepest value. And today's deal with Sorby Hills and the last two transactions that I mentioned, we're just continuing to find really attractive royalties on projects that are being fast-tracked into production. I would expect we continue to be 70% Australia-weighted. And then on asset concentration, we're very careful not to be overweight one asset. There's been a long list of royalty companies that have had troubles if 20%-40% of their NAV gets skewed to one asset. So I think we'll try and aim to be 15% maximum asset concentrated. And then gold, I think, will continue to be 70%+ of our weighting going forward.
Excellent. Well, thank you very much. Appreciate you joining.
Thanks for your time, everyone.