Elsewhere in the investment companies sector partial exposure can be achieved via a number of trusts, most notably Scottish Mortgage, which has 15 per cent of its portfolio in unlisted companies, including the 'hectocorn' that is Ant Financial.
The latest results from the trust highlight the exceptional returns that have been achieved from private investments since making its initial investment in 2010, which have exceeded the impressive gains seen in its listed portfolio.
As exciting as all this potential is for the long-term future, I cannot help thinking that against a backdrop of decelerating global growth and the move from quantitative easing towards quantitative tightening, there may be better times to join the unicorn hunt.
Consequently, I did not participate in the Merian launch but I will follow its progress with great interest.
An alternative way to access private companies is through listed private equity trusts which typically trade at quite big discounts to net asset value. Although they are not directly comparable to the new wave of trusts and typically only offer limited exposure to unicorns, they do benefit from being able to exercise greater control over their underlying investments than minority investors.
They also have an enormous potential investment universe as there are estimated to be more than 1.5 million private companies around the world that could accept private equity investment.
Listed private equity trusts, such as HG Capital, ICG Enterprise, Pantheon International and Harbourvest, have delivered market-beating returns over the long term and are well placed to benefit from the trends in private company investment.
As with all forms of equity investment there will be bumps along the road and investors need to take a long-term view, but I continue to favour a structural bias towards private equity within my portfolio.
Peter Walls is manager of Unicorn Mastertrust