Regencell Bioscience Limited rose 16% in premarket trading after soaring nearly 17600% this year.

Hong Kong-based Regencell Bioscience Holdings Ltd., which develops herbal treatments for ADHD and autism, saw its shares soar more than 82,000% from a February low.

In interim financial results released Monday, Regencell — which has reported six consecutive years of net losses — pointed to short sellers as a possible cause of its stock’s extreme volatility.

“We believe that a ‘short squeeze’ due to a sudden increase in demand for our ordinary shares that largely exceeds supply has led to, and may continue to lead to, extreme price volatility,” according to the filing. It added that nothing has changed about its operating performance or financial position.

At the shares’ June 17 peak, founder Yat-Gai Au’s 86% stake was worth $33.3 billion, according to the Bloomberg Billionaires Index, putting him ahead of such rich-list stawarts as Phil Knight and Masayoshi Son. His net worth has since dropped to $6.8 billion.

Some experts, including S3 Partners’ Ihor Dusaniwsky, questioned Au’s explanation for the price swings, saying “it doesn’t hold water.”

Regencell’s current short interest is only about 1 million shares, or just 3% of the company’s already low float, data from S3 Partners shows. Given those numbers, it’s unlikely that short sellers wield enough muscle to move the share price significantly, Dusaniwsky said.

“Looking at the size of the short selling compared to the trading volume, it can’t be the cause,” Dusaniwsky, the firm’s managing director of predictive analytics, said in an interview.

Regencell’s outstanding shorts as a percentage of float briefly spiked to above 40% on March 18, as the company’s shares climbed from 10 cents to more than $1. Short interest quickly returned to below 5% three weeks later, where it has remained. There was no significant change in the number of outstanding shorts in mid-June, when Regencell’s shares climbed to their peak of $78.

“Long buying and long selling was by far the primary driver of its price moves,” Dusaniwsky said. The number of shorts “are a drop in the bucket compared to total average trading volume.”

A spokesperson for the Securities and Exchange Commission, which regulates short selling, declined to comment, while attempts to reach Regencell were unsuccessful.

In its interim financial report, Regencell disclosed a $1.9 million net loss for the six months ending Dec. 31, 2024. It has lost money in every reporting period since 2019, filings show.