Analysts called today’s $18 billion notional expiry of Bitcoin options “record-setting,” adding that whatever volatility arises from it may be delayed.

That may be welcomed news for crypto investors after a rough trading week has sent prices tumbling across the board, with Bitcoin hanging on to a slight gain for the month of September and the rest of the crypto market already in the red.

“Historical precedent suggests that large expiries often suppress volatility leading into the cut-off, then result in a clearer directional move in the 24-72 hours that follow,” Bitfinex analysts told Decrypt.

That expected volatility has left users on Myriad, a prediction market owned by Decrypt parent company Dastan, thinking Bitcoin will see more red than green candles over the weekend, meaning lower prices on the daily charts. The bears are narrowly edging out the bulls at the time of writing, 51% to 49%.

Options are derivatives contracts that give traders the right—but not the obligation—to buy or sell Bitcoin at a set price, the strike price, on or before a certain date. Calls bet on higher prices and puts are bets that the price will go lower. It’s a popular way for traders to hedge risk.

Most crypto options expire on fixed monthly cycles, usually the last Friday of the month. And when the notional value of options expiries stretches into the tens of billions of dollars—as it has this month—it can create some volatility in markets as traders rush to rebalance their risk.

Looking ahead to October, the Bitfinex analysts said there’s still a lot of risk sitting in the options market. At the time of writing, crypto data aggregator Coinglass estimates there’s $78.9 billion worth of open interest in Bitcoin contracts.

On Deribit, the largest Bitcoin options trading platform and recently acquired by Coinbase, there’s already more than $8 billion worth of open interest slated to expire on October 31.

“Total aggregated BTC options open interest remains at highly elevated levels,” the Bitfinex analysts told Decrypt. “There has been significant build-up in October-dated calls, concentrated in the $115,000 to $125,000 corridor.”

The analysts also noted that the Bitcoin options market shows signs of “long convexity.” That means traders who bought those long contracts will see huge gains if BTC experiences a sharp rally.

But the dealers who sold those options are positioned in ways that could force them to hedge aggressively if it happens. That could leave the dealers buying BTC as it rises and selling as it falls, which would exaggerate intraday swings and create a lot of chop in the options market.

If that happens, they added, it could “suppress upside movement until flows or spot-driven factors break the structure.”