Weinstein's Saba Capital Management wants to seize control of seven trusts it owns sizeable stakes in, after accusing the 160-year-old sector of widespread underperformance, which the trusts reject.
In an initial salvo, shareholders in Herald Investment Trust , the largest of the seven, voted decisively against Saba's bid to unseat its board last week.
Next up are Baillie Gifford US Growth Trust and Keystone Positive Change Investment Trust, which hold votes on Monday. Three others follow on Tuesday and Wednesday.
"Boards and managers have to take note as any trust languishing with a liquid portfolio on a wide discount without any discount control mechanism is vulnerable," said Daniel Lockyer, Hawksmoor Investment Management senior fund manager.
Investment trusts are listed vehicles that individuals can buy shares in to gain exposure to assets, from listed stocks to hard-to-access private companies.
Their shares should trade broadly in line with the net value of their assets (NAVs). But trust shares can fall out of favour, creating big gaps between share prices and NAVs, and leaving investors unable to cash out without leaving value behind.
Win or lose, Saba's battle looks likely to mean more pressure on trusts to improve their performance.
"Saba's campaign has already set a powerful precedent," said Sonia Falconieri, professor of finance at London's Bayes Business School. "The message is clear: performance and governance will remain under intense scrutiny."
A Reuters analysis of the seven targeted trusts' most recent accounts - filed between April and November last year - shows a £350-million total shortfall between the value of the shares at the filing date and the £3.9-billion book value of the assets the trusts held.
While those figures only capture a snapshot in time, the filings show discounts are persistent.
Trusts say they have delivered respectable long-term performance, that trading improved in 2024, and that they are taking action to close discounts. They call Saba's campaign self-serving.
Weinstein has vowed to fix performance by merging unpopular trusts, buying back shares, and investing in more private assets rather than large listed stocks.
In an interview before Herald's vote, Weinstein, who agreed a standstill this month in a long-running battle with dozens of BlackRock trusts, told Reuters he was preparing for the long haul.
"If we lose narrowly, we may win in some period not that far thereafter," he said, adding that at least two institutional investors had handed him fresh cash since his campaign went public late 2024. He declined to name them.
In the meantime, trusts are trying to rally shareholders.
Edinburgh Worldwide Investment Trust's Chair Jonathan Simpson-Dent accepts discounts have widened. But he said the sector was already focused on fixing it.