big banks weren’t enough for stock investors, Friday brings a critical moment where many option traders must decide their next move on hedging.

About $1.9 trillion of options are set to expire, obliging investors to either roll over existing positions or start new ones. The monthly event includes $925 billion of S&P 500-linked contracts and $395 billion of derivatives across single stocks scheduled to run out, Goldman Sachs Group Inc. estimates.

With the S&P 500 down more than 20% from its January peak, a question looming large is how much insurance a long investor actually needs. Intraday volatility has whipped up this week -- though that included two straight sessions in which the Nasdaq 100 reversed major dips. The decision of whether to renew hedges is a complicated one for professional speculators.

“A lot of investors and traders have been in cash, or higher cash than they were at the beginning of year and so have less of a need to hedge,” said Michael Purves, founder of Tallbacken Capital Advisors. “A lot has been priced in.”

With daily options volume heading for an annual record, the expiration is a widely watched event on Wall Street. Moves in the derivative market have the capacity to spur gyrations in underlying securities. There are signs that demand for options hedging is waning as money managers have cut their equity exposure and some opted for other ways such as index shorting for protection during the rout.