Turntide Technologies, a maker of electric motor systems backed by Bill Gates–founded Breakthrough Energy Ventures, was one of the more than 300 private companies that passed the $1 billion valuation threshold last year, putting it firmly into unicorn status. It’s not worth close to that anymore. The Sunnyvale, Calif., firm is nearing a deal for new capital that would likely slash its valuation by more than 80%, according to corporate filings and executives.

The trickle of down rounds that has hit the startup world over the past year is starting to become a flood, investors and lawyers say. In the most extreme cases, companies like Turntide are planning “cram-down” rounds of financing, which heavily dilute some existing investors’ stakes with diminished valuations. Investors at autonomous-delivery startup Nuro have discussed a similar move. Likewise, internet answer site Quora has recently wiped away some of its investors’ preferred ownership rights in a corporate filing, a move that often foreshadows cram-downs, lawyers say.