Biotechnology stocks faced their worst April on record, and more pain may be ahead for biotech-focused exchange traded funds (ETF).

Popular biotech-focused ETFs like the SPDR S&P Biotech ETF (XBI  ) and the iShares Biotechnology ETF (IBB  ), have fallen about 33% and 21% so far in 2022, respectively. Moreover, biotech stocks in the Russell 2000 (IWM  ) had their worst April in at least 25 years, according to Bloomberg, with the sector down 65% from its February 2021 peak, plunging 22% in April alone.

The sector faces multiple headwinds including regulatory concerns and market participants moving to unload riskier assets due to concerns over slowly global economic growth.

Jefferies strategist Will Sevush told Bloomberg in a recent interview that recent trends in the biotech sector mirror the dot-com crash of the early 2000s experienced by the tech industry. Sevush said the tech crash was led by high investor interest, especially amongst retail traders, in early stage companies that had yet to generate much when it comes to revenue.

Sevush warned that if early stage biotech companies continue to follow the trends that lead to the dot-com era crash, the sector may not reach a low until next fall.

"Biotech saw a very deep scrape for therapeutic assets that are very early in development where you haven't seen that many IPOs," Sevush told Bloomberg. "It matches the zeitgeist of the Nasdaq 2000 crash."

Moreover, Piper Sandler analyst Christopher Raymond, who tracks fund flows in the biotech sector, told Bloomberg that a market sell-off usually reaches its low when the ratio of inflows to outflows falls below 0.3%; the last time the XBI reached that low it rallied higher in the months that followed.

The firm's analysis showed that the biotech's current ratio fell to 0.58 last week, meaning that there may still be more losses ahead for the sector.