Policymakers should step into the equity market and buy stocks, as Hong Kong did in 1998, to shore up equity markets after recent precipitous falls, according to Sir Michael Bunbury.
Central banks began this week with co-ordinated policy action to protect economies, with UK's Chancellor Rishi Sunak promising a £330bn rescue package for companies and transport secretary Grant Shapps floating the idea of temporary nationalisation of airlines, rail firms and bus companies.
Across the pond, the US Federal Reserve has announced a swathe of interventions to ensure liquidity continues in markets.
But Bunbury, who chairs a number of investment trusts, said he had been disappointed no central bank has yet entered the stockmarket, as Hong Kong did at the depths of the Asian crisis more than 20 years ago.
With Hong Kong's currency under attack from speculators and its equity market having halved, the government became the second or third largest shareholder in 33 companies as it bought a portfolio of equities in August 1998. By mid-1999, the market had recovered and reached a record high the following year.
Bunbury, speaking in his role as chairman of BH Global, said that with the UK Government able to borrow at all-time low rates, and the yield on a number of blue-chip stocks exceeding 6%, buying a basket of stocks was a "no brainer", though conceding it was "probably politically a step too far for this country at this time".
Speaking on Monday, Bunbury, who also chairs Harbourvest Global Private Equity, told Investment Week: "I am delighted that central banks have reacted so quickly. I'm sorry it hasn't had a more stabilising effect today."
With interest rates having been slashed to near-zero by both the Bank of England and US Fed, Bunbury noted that "central banks are very short of ammunition".
"It is pretty clear to me that for a major economy like the US or the UK to introduce negative interest rates other than for a very short time [would] have some very nasty side effects," he added.
"Amazed though I was by the Budget, coming from a so-called Conservative Government, I think generally the trend of it was absolutely right. You need Keynesian, reflationary measures.
"The best of all would be some helicopter money - dropping £1,000 into every citizen's bank account and encouraging them to spend it would probably have the quickest effect. But, again, that is probably a step too far."
Overall, Bunbury said it was impossible to predict what would happen to markets in the short term. "This is really a very, very serious situation," he continued.
"Unlike 2008/09, where it was principally a banking and financial sector problem, this is a very big, real company problem.
"This time, profit warnings from companies are going to flow like fluttering autumn leaves, and I'm afraid some of those companies may well not survive. I would not like to be an operator of a cruise line at the moment just by way of example."
However, he added, "I know that eventually, once the clouds clear, equities will be the place to make money again".
BH Global, which is a hedge fund run by Brevan Howard, has been one of the best-performing investment trusts in recent weeks. The fund, which takes positions in interest rates and foreign exchange, gained 11.4% in the one month to 17 March, according to FE fundinfo.