Britain's largest charity made more than $100 million when Twitter went public earlier this year, it has been revealed.
The Wellcome Trust reportedly purchased a 1% stake in the social network from private investors, employees and founders about two years ago.
But after the firm's IPO last month the value of that investment shot up rapidly. Twitter's stock price is currently hovering around $56 per share, meaning its share is worth about $313 million.
The Wellcome Trust funds scientific and medical research, and is also one of the UK's largest investors.
In its annual report, released on Wednesday, the charity said the value of its endowment increased by 18% over the last year, amounting to a return of £2.6 billion on a total investment portfolio worth £14.5bn.
The charity admitted that it had marked up its investment "by more than $100m" but a report by Management Today established that the total stake is around 1%, with a value of at least $300 according to the current share price.
Among its other investments is a 1% stake in Facebook, worth more than $185 million, and a £216 million investment in Vodafone.
Danny Truell, CIO of the Trust, said in a statement:
"Our internal investment team and external investment partners across the board again added significant value, enabling us to perform better than global stock markets with considerably lower volatility.
“It will be a stretch to continue to achieve returns of 10 per cent a year over the next decade, but the businesses and partnerships in which we have invested for the long term generally continue to reinforce their franchises.”