Several electric vehicle and mobility startups went public and raised money in the past two years by merging with special purpose acquisition companies. Now, as companies find it far more difficult to raise cash, they are turning to unusual methods.

Scooter rental service Bird, electric truck maker Nikola and electric vehicle startup Canoo are among the companies that have agreed to pay hedge funds or investment banks a fee for the option to sell additional shares, usually over a two- to three-year period, according to securities filings. The hedge funds and banks generally can buy the shares at a small discount.

These deals, referred to as equity lines of credit or share price agreements, provide an alternative to sources of cash that once were more readily available, such as secondary stock offerings. But those funding sources are becoming harder to access as markets tumble and investors grow wary of companies that are burning cash. (See our chart below of recent deals.)