Barclays says Silicon Valley is the real reason UK firms look to New York
Key Points
- Tech made up over 90% of US follow-on raises in H1 2026, up from 30% in 2020
- Barclays credited Silicon Valley's pull rather than a general US market advantage
- London trading holds up for firms worth $1 billion to $10 billion
- UK firms get more analyst coverage than US peers up to £5.5 billion
- UK IPO activity remains at historically low levels since 2022
Tech firms raised over 90% of US follow-on money this year, Barclays said.
The bank’s capital markets team published the finding this week in a new report which looked at how companies in London, New York, Hong Kong and Europe raise money after listing on the stock market.
In 2020, technology companies accounted for just over 30% of money raised through follow-on share sales in the US. By the first half of 2026, technology, media and telecoms firms made up more than 90% of that total.
Barclays said this points less to a general US market advantage and more to the pull of one powerful industry. It said the cluster effect of Silicon Valley continues to draw both companies and investors to American exchanges.
UK fundraising covers a much wider range of sectors, according to the report. Energy transition companies led UK follow-on raises in 2025 and the first half of 2026, with the rest spread across financial, healthcare, natural resources and industrial firms.
The size gap
US IPOs have raised £340 billion since 2015, against £12 billion for UK listings. US-listed companies raised a further £691 billion through follow-on share sales, while UK-listed firms raised £127 billion.
Follow-on raises made up 92% of all money raised on UK markets since 2015, compared with 67% in the US. Barclays said 56% of UK companies listed since 2015 have come back for more money at least once, and 34% have done so twice.
Where London holds up
The report found that companies worth more than $500 billion drive most of the headline US trading advantage. For firms valued between $1 billion and $10 billion, trading volumes in London tended to run ahead of the US and Europe.
The gap between buying and selling prices for FTSE 100 shares averaged 0.068%, close to the S&P 500’s 0.042%. Barclays said the real weakness sits with smaller UK companies, where that gap widens to 0.495% across the FTSE All-Share.
UK companies valued up to £5.5 billion also get more research analysts covering them than similarly sized US firms in almost every size band. Barclays said this coverage helps smaller listed firms get noticed and return to investors for more cash.
US listings typically see bigger share price jumps in their first days of trading, but those gains often fade within weeks. UK listings saw smaller early rises but held their value more steadily, with Main Market listings since 2020 trading around 5% to 7% above their IPO price after six months.
Barclays also tested whether investors systematically undervalued UK shares at the height of the 2024 and 2025 debate over companies moving their listings abroad. In oil and gas and pharmaceuticals, it found valuation gaps with US peers mostly reflected differences in company performance rather than where the companies listed.
“When businesses need to raise significant capital, move at pace and fund growth, public markets still offer real advantages,” said Tom Johnson, Global Co-Head of Capital Markets at Barclays.
The bank acknowledged the pressure on London in the same report. UK IPO activity, measured against the size of the economy, has fallen to historically low levels since 2022 and remains below both the US and Europe.
The UK has rewritten its listing rules several times since 2020. The changes include a three-year stamp duty holiday on new listings from November 2025 and a faster process for follow-on fundraising introduced in January 2026.
