Cannabis companies have been lighting up stock markets across the pond over the last year and the fledgling companies focused on the drug that have listed over here have been equally buoyant.
Shares in mostly Canadian-listed companies involved in cannabis have been on a tear over the last year, in the run-up to the country's legalisation of the drug for recreational use this month.
The sector has even spawned a raft of exchange-traded funds (ETFs), such as the £460 million Horizons Marijuana Life Sciences Index ETF (HMMJ.TO).
But far from pushing the stocks up further, Canada's legalisation of the drug, which came into effect last Wednesday, has provoked a sell-off, in what appears a case of 'buy the rumour, sell the fact'.
Few UK fund managers running US or global funds have dipped their toes into the fledgling sector.
He backed the initial public offering (IPO) of Tilray (TLRY.O) on the US Nasdaq exchange in July.
The offering was priced at $17 per share, but within two months the shares had rocketed more than 1,150% to $214.
They have since halved from that peak, but not before Weldon banked some of the explosive gains.
'This was a rather unusual investment for us – but it has produced good returns,' he said in his most recent update to investors.
'We bought Tilray at its recent IPO (having met with the company twice in the past 12 months) as we believe its scale will lead to success.'
'The resultant euphoria in Tilray's share price gave us an opportunity to sell the vast majority of our holdings at a significant profit.'
Tilray is not Weldon's only investment in the space. He bought Canopy Growth (WEED.TO), the largest cannabis stock by market cap, in January, and Aphria (APH.TO) in June.
Those investments haven't proved quite as explosive, though Canopy is up by around 70% since January, and Aphria by around 25% since June.
Weldon highlighted the boost to his fund from his exposure to the sector in his third quarter update.
'Canada has been early in legalising marijuana and we are seeing increased signs that more countries may follow it,' he said.
'Canadian companies will have an early mover advantage and we believe this will matter as the markets develop.'
Weldon said drinks maker Constellation Brands' (STZ.N) building up of a stake in Canopy Growth had also helped drive the rally in cannabis stocks, 'as investors recognised that these companies could gain sizeable investments from large pharmaceutical, alcohol and consumer products companies'.
Weldon's cannabis investments have been among the holdings powering a strong run over the past year, with his fund the top performer in the Investment Association's US Smaller Companies sector over the 12 months to yesterday, up 17%.
Over in the UK, the investment rationale for cannabis companies is a different one. With legalisation for recreational use not on the agenda, investors are pinning their hopes of breakthroughs in the medicinal space.
One UK company involved in the space has been around for years: GW Pharmaceticals (GWPRF.PK), which grows cannabis in fields in southern England for medicinal use, followed its 2001 Alternative Investment Market listing with flotation on Nasdaq five years ago.
Dobell has been an investor for 15 years, and the stock has reached new heights this year, jumping to an all-time high at the end of last month after the US Drug Enforcement Administration changed its stance on the company's cannabidiol-containing drug, placing it in 'Schedule V', those with the lowest potential for abuse.
Since listing on Nasdaq in 2013 at $8.90 a share, they have risen 1,460% to today's $138.85 price.
With GW Pharmaceuticals having long departed the AIM market, investors looking to play the cannabis boom with UK shares have been left disappointed.
But this year has seen the launch of two medicinal cannabis investment vehicles on the NEX Exchange, an even more junior rival to AIM.
Sativa Investments (SATI.ISD) and High Growth Capital (HASH.ISD) floated in March and June respectively and both have attracted fund manager backing.
Gervais Williams (pictured) is a backer, having invested £500,000 of his £186 million Miton UK Smaller Companies fund in the stock in June, and lending the company further backing with a bigger investment in its £3.8 million share placing last week. That has seen Sativa also added to the portfolio of Miton UK Micro Cap (MINI) investment trust.
Sativa will join High Growth Capital in the portfolio, with Williams having acquired 4.9% of the company's shares, a position that was later trimmed to 3.8%, according to stock exchange filings at the end of July.
Both managers have been rewarded with big jump in the shares, inflating the value of their, admittedly small, positions. Shares in Sativa are up nearly 180% on the 4p price at which Miton invested in June, trading today at just over 11p.
High Growth Capital has meanwhile done exactly that, with the share price doubling in just the last three weeks.
The catalyst for these big jumps has been home secretary Sajid Javid's decision to allow use of the drug for medicinal purposes, announced earlier this month.
The drug will be available on the NHS from 1 November, after the government came under pressure from high profile campaigns, including that led by the mother of epilepsy sufferer Billy Caldwell.
Williams said that given insufficient provision of the drug, the scope for a company like Sativa to produce a strong return on investment was high.
'There is the opportunity for making an unusually high margin. There are so few suppliers out there,' he said.
He added that the initial investment in Sativa was one where the downside risk was limited, but the upside potentially very high.
'When we first invested, the market capitalisation was very small,' he said. 'You are not investing with a lot of expense. The optionality is so large but the entry price is so low.'
With Williams and Hargreave the only small cap managers to have been drawn to the new companies, the Miton manager said he wasn't surprised to find himself in relative isolation.
'A lot of small company fund managers don't look at such small companies, he said. 'There's sometimes less competition.'