Snap stock has been a hugely popular short position since the moment it first became available to borrow, and it’s still so popular that some short-sellers may be about to get squeezed out of their positions. Snap stock is on the rise today — surprisingly — but at the time of this writing  anyway, it’s probably not enough to be a short squeeze unless it’s in the extreme early stages.

Snap stock short interest hits $1 billion

Earlier this week, short interest in Snap stock surpassed $1 billion, according to financial analytics firm S3 Partners. The firm also explained that short interest in the name has been range-bound between $730 million and $900 million during the second quarter thus far.

However, S3’s Ihor Dusaniwsky added that when Snap stock tested the $18 support level, short-seller boosted their positions as it rallied near $21. As of this writing, Snap stock is closing in on $21 again. Short interest in the name reached $1 billion on Tuesday after nearly $200 million of new short activity in the week before, including Tuesday.

Nowhere for Snap stock to go but up

As far as shorts go, Snap stock has been a profitable one, according to Dusaniwsky. Short-sellers were up $44 million from the IPO through Tuesday, so it’s no wonder short-sellers tacked $174 million onto their position since the end of the first quarter. Short interest in the name quickly hit $827 million within the first month after the initial public offering on March 2.

He explained that $1.001 billion is a key milestone. There can be very little growth beyond that because it means almost all of the Snap stock that was available to borrow is out on loan.

A short squeeze in Snap stock?

It has also gotten more expensive to borrow Snap stock, as borrow rates on existing shorts have climbed to a fee of 5% to 7%. It’s even more expensive to open a new short position, Dusaniwsky added, as borrow rates for new positions have skyrocketed to fees of 45% to 60%. He also expected rates on existing short positions to quickly rise because he said on Tuesday that there was “virtually no stock borrow supply left.” Additionally, lenders had recalled more than 1.5 million shares.

The S3 Partners research chief predicted then that if demand to borrow shares of Snap remained strong, borrow rates could near the 100% fee level within the next week. When you combine a lack of Snap stock to borrow, high borrow rates, active borrow recalls and a rising stock price, it means a short squeeze could be imminent.

Further, the lack of available shares to borrow means investors who are long Snap stock will be controlling price moves.

“If SNAP’s stock price declines it will because of long shareholders selling their stock and if SNAP’s stock price increases it will be because shorts are buying to cover their positions and longs are bidding up the stock price as they build their positions,” Dusaniwsky clarified.

So who is long Snap stock?

Short interest in Snap has been so hot since the first day it became available to borrow that a lot of the focus has been on the short side, but regulatory filings revealed earlier this week that some very big names own Snap stock, or they did as of the end of the first quarter anyway. For example, asset manager BlackRock and mutual fund giant Vanguard both had long positions, according to 13F filings. George Soros’ hedge fund and Dan Loeb‘s Third Point were also still holding shares at the end of March.

Of course any or all of these and the other big names who were holding Snap at the end of the first quarter may have dumped all of their shares at this time. We won’t know until the next batch of 13F filings is released in July.

Snap shares rose by more than 2% during regular trading hours today, climbing as high as $20.58.