Retail investors poured money into markets as equities embarked on a nearly record-run of all-time highs in June. Whether they’ll stick around when volatility inevitably resurfaces remains to be seen.

Last month, TD Ameritrade’s Investor Movement Index -- a measure that has tracked clients’ positioning in the market since 2010 -- rose to the highest level on record, according to data released Tuesday. The influx came as trading volume dropped off while the S&P 500 hit five consecutive record closes to end the month, en route to the longest streak since 1997.

But while big rallies in client favorites such as Apple Inc. and Microsoft Corp. boosted optimism among retail traders, they waded into a market as calm as it’s been in 15 months. The Cboe Volatility Index -- known as the market’s fear gauge -- slipped to its lowest level since February 2020 as trading activity cooled. Meanwhile, waves of anxiety are building beneath the market’s placid surface, as delta variant fears collide with concerns of peak economic growth.

“Apple and Microsoft have been stocks that our clients have gone to over the past couple of months, and with those leading the way in June, I think that gave people a lot more confidence in the overall market,” JJ Kinahan, chief market strategist at TD Ameritrade, said in an interview. “It’ll be interesting to see if volatility comes back, if that starts to change people’s opinions and exposure to the market.”

Apple and Microsoft gained 9.9 per cent and 8.5 per cent last month, respectively, helping fuel the S&P 500 higher for a fifth straight month. Meanwhile, a Goldman Sachs basket of stocks favored by retail traders climbed 5.8% last month in its best showing since January.

However, that potential for turbulence was on display Tuesday, when the S&P 500 dropped as much as 0.9% in its biggest drop since mid-June.

TD Ameritrade clients were net buyers in June, with Airbnb Inc., Alibaba Group Holding Ltd. and Coinbase Global Inc. among the most popular picks, the report said. Some of the most-offloaded names included Eli Lily & Co., Moderna Inc. and Peloton Interactive Inc.