Wolfspeed shares jumped another 15% in premarket trading on Tuesday.

Wolfspeed stock surged on Monday, just days before the semiconductor manufacturer is set to report its fiscal third-quarter earnings.

Shares climbed 26% to $4.13 even without significant news that had the potential to lift the stock. Wolfspeed was in position to close with a fifth consecutive day of gains, marking the best stretch since the five days ended Oct. 17, when it rose 71%, according to Dow Jones Market Data.

Efforts by short sellers—traders who bet that a stock’s price will fall—to close out their positions may be behind the surge. Short sellers borrow stock and sell it, hoping to buy shares at a lower price and return them to the lender, pocketing the difference as a profit.

That tactic can run into trouble if a lot of stock is borrowed and sold short. A sudden rise in the price can create a stampede for the exit that sends the price higher, putting even more pressure on short sellers to close their positions.

Raymond James analysts noted in their latest semiconductor industry report that aggregate short activity increased 5% in early April versus late March. Wolfspeed topped the list of stocks with the largest short-interest ratio, at 41%. The figure is calculated by dividing the amount of stock sold short by the average daily trading volume.

The company, which is due to report its earnings on May 8, designs and manufacturers so-called wide bandgap semiconductors, which allow devices to operate at higher temperatures and voltages.

The company’s second-quarter earnings report, released at the end of January, said its net loss grew to $372.2 million from $125.9 million a year earlier.

Wolfspeed told investors to expect third-quarter revenue from continuing operations in the range of $170 million to $200 million, as well as adjusted net loss in range of $138 million to $119 million. Investors will be looking to see if these numbers hold up.

The company said last month that it was taking steps to strengthen its capital structure. Wolfspeed said it had received $192.1 million in cash tax refunds from a tax credit for advanced manufacturing that was established under the Chips Act in 2022.