When the stock market was plunging Feb. 2 to Feb. 9, Vanguard Group investors may have jammed the company's phone and internet, but they didn't panic, mostly: Over that six-day period, "97 percent of households didn't trade," the company says, citing sampling it did among 8 million fund investors and 401(k) retirement plan members.

Compared to what? For example, on Monday Feb. 5, "one percent of Vanguard houses traded," moving 0.3 percent of Vanguard assets — compared to a little over 0.1 percent of assets on "a typical day," Vanguard spokeswoman Alyssa Thornton told me. So you could say trading tripled, but most account owners still didn't surrender and dump their funds.

Of course, "their website was down during the most volatile trading hours," noted a poster on the Bogleheads Website who went by the moniker "Rudeboy." "That's like an employer locking his workers in the factory and saying, 'Look! No turnover!'"

Or, Daniel Wiener, publisher of the Independent Advisor for Vanguard Investors newsletter up in Brooklyn, put it: "Isn't it kind of tough to trade if your website isn't working?"

Among those who did get their orders in, there was "less 'buying on the dip' in response to volatile markets," a sign investors were "growing more skeptical about stocks," Thornton said. (Updated)