NEW YORK, United States — All the love for Snap Inc. is sure to draw out the haters.

That’s the view of S3 Partners LLC, a financial analytics firm, which says short interest in the photo-app maker is liable to reach $1 billion within a week, particularly if today’s rally continues. The contrary bet won’t be cheap, either, with the cost to borrow shares likely to start at 25 percent and rise.

“There is a strong chance that the initial IPO rally will continue into a follow-up rally, which will spur even more short demand,” Ihor Dusaniwsky, head of research at S3, wrote in a note. “Stock borrow availability will be tight initially.”

A follow-up rally is on. Snap surged 44 percent Thursday on the first day of trading, and the stock gained an additional 14 percent to $27.83 as of 12:08 p.m. Friday. The Venice, California-based company raised $3.4 billion in an initial public offering, pricing the shares above the marketed range.

S3’s analysis is based on how bearish bets evolved in other recent IPOs, particularly Twilio Inc., the San Francisco-based web-applications maker that went public last June and saw short interest reach 20 percent of the shares sold. Logically, the more a stock rallies out of the gate, the more shorts are drawn to it, S3 said.

“We expect that 10 percent to 20 percent of the initial offering will be shorted in the first week of trading, which roughly translates into $500 million to $1 billion of short interest right from the start,” it wrote.

Should Snap continue to rally and short interest get above 25 percent, borrowing costs may climb to a range of 30 percent to 50 percent, the firm estimated.

Investors will have new ways to hedge positions next week as CBOE Holdings Inc. plans to start trading Snap options on March 10.

By Lu Wang; editors: Arie Shapira, Chris Nagi & Richard Richtmyer.