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.”

Loading Slideshow...
  • Dog Restrainer

    If you're not trying to cut your dog in half, you have no business using this device. What's wrong with a good, old-fashioned leash?

  • Baby Cage

    Does your baby take up too much space? Is it too stinky? Thankfully, there's <a href=",28804,1991915_1991909_1991746,00.html">this baby cage</a> that allows you to suspend it out your window! (Photo by Reg Speller/Fox Photos/Getty Images)

  • Noodle Eater Hair Guard

    Ponytails are so passé. The best way to keep your hair out of your noodles: <a href="">masks made out of paper plates</a>.

  • Cigarette Rain Guard

    Because sometimes it's raining so hard that even your <a href="">cigarette needs an umbrella</a>.

  • Self-Stirring Mug

    Can you get any lazier? Credit: <a href="">ThinkGeek</a>

  • Face Protectors for Snow Storms

    For all of those times when a hat isn't enough to keep you warm, you can look like one of those <a href="">creepy monsters from Beetlejuice</a>? Credit: <a href="">Flickr</a>

  • Neck Cleaner

    "Five-year-old Tim Gregory wears, under protest, a brush that cleans a child's neck without the use of soap and water in Los Angeles, Calif., Jan. 12, 1950. The plastic collar brush will dry-clean the youngster's neck thoroughly as he plays. The brush was developed by the Los Angeles Brush Corp. at a mother's suggestion." What ever happened to a good old fashioned bath? (h/t <a href="">Business Insider</a>)

  • Portable Record Player

    Sure, records player are bulky, but so are records! We're having trouble seeing the point of this one. Credit: <a href="">ThinkGeek</a>

  • Flexible Flyer Snowball Maker

    Because making snowballs is so difficult. <a href="">Snowball Maker</a>.

  • Baby Carrier

    "Jack Milford, player with the Wembley Monarchs ice hockey team, has invented a carrying device so that his baby can join his wife and himself on the ice." Ice skating is more important to this man than the safety of his child. (h/t <a href="">ByuTV</a>)

  • Personal Sauna

    An <a href="">effective way</a> to roast yourself to death. (Photo by Yale Joel/Life Magazine/Time & Life Pictures/Getty Images)

  • Baby Mop

    At least the baby will have a great immune system after some time being used as a mop and <a href="">bathing in dirt</a>.

  • Double Ended Pipe

    For when you and your friend want to <a href="">conserve tobacco</a> while also sharing a tender moment.

  • QuikPod Handheld Convertible Tripod

    For the <a href="">"selfie"</a> addict with short arms. <a href="">QuikPod</a> Handheld Convertible Tripod. (Amazon)