Trying to catch market bottoms is a treacherous business, but if you’re going to try it, keep an eye on the Vix index.

Volatility, as measured by the Vix, has eased recently, after peaking at 35 in early May. That’s a high reading suggestive of elevated fear levels, but it might not be high enough, according to a report by 3Fourteen Research founder Warren Pies.

The Vix was one of 10 indicators in a checklist to monitor for signs of a market bottom. In the past 30 years, the VIX has hit 40 eight times, the report noted. In seven cases, the selling pressure was near its end. A Vix at or above 40, says Pies, is generally “a decent level to begin looking for a bottom”.