City "superwoman" turned movie mogul Nicola Horlick is planning to raise a $250m (£146m) war chest to finance Hollywood film projects.

With her new vehicle, Glentham Capital, the former star fund manager has switched her investment focus from the stock market to the film industry and now spends her time reading film scripts rather than company reports.

"I have not suddenly become starstruck and rushing off to Hollywood," she said. "It's to do with the investment returns."

Glentham Capital will on Monday launch a second round of fundraising on equity crowdfunding platform Seedrs. The aim is to raise £450,000 on top of the £150,000 seed capital raised last year.

There has been a backlash against film industry investment in recent months after some ventures were linked to alleged tax avoidance but Horlick insists Glentham Capital is "completely above board".

Investors in the fund manager are eligible for tax breaks under the government-backed Enterprise Investment Scheme (EIS) designed to encourage investors to put money into creative industry startups.

"Because it is in the EIS scheme it is all pre-approved by HMRC," said Horlick who is Glentham's chief investment officer and chair. "A lot of things that have gone wrong have not been approved by HMRC."

Seedrs investors are buying a stake in Glentham Capital, rather than the underlying funds, with their return based on its success as a fund manager. The fledgling fund management outfit is also relocating from Guernsey to Delaware in the US as Horlick says "that's where the investors are".

She initially set out to raise $100m but has since raised the bar to $250m after receiving a high level of interest, including a $20m anchor investment from a wealthy American family. The Glentham film fund – other types of fund are to follow – will have the first look at the films developed by Horlick's production company, Derby Street Films.

To date the company has made the action film In the Blood and will next year shoot Blood Mountain, starring Benedict Cumberbatch.