(Bloomberg) -- It's like rubbernecking after a car accident: Themarket sinks dramatically, as ithas for most of 2016, and virtually everyone with a401(k) plan suddenly can't lookaway from the wreckage.

As key indexes first started going south earlier thismonth, almost 4 million people contacted Fidelity on January 4alone, either online or by phone, to check on theirretirement savings.

"That was an all-time high," said Jeanne Thompson, vicepresident of Fidelity Investments, which manages 13 million401(k) accounts with over $1 trillion under management.

The company said it's too early to discuss web traffic orcall volumes from the current week of carnage.

The first four business days of this year, which were alsopainful on Wall Street, are four of Fidelity's top sixdays of all-time contact volume.

At T. Rowe Price, which had nearly $300 billion inretirement assets under management as of September, phonevolumes over the first week of January were 56 percent higher thana typical day and web traffic spiked by around 30 percent overnormal.

Both Fidelity and T. Rowe Price reported a similarphenomenon when the markets had a dark moment back in August."Nervous investors are calling or checking in with the web,"said Judith Ward, a certified financial planner at T. RowePrice.

But it's mostly just savers who want to gawk at anunfolding mess, a way to feel like you're takingaction without actually making panicked moves.

"In terms of doing a transaction, the majority are doingnothing," said Ward. During the August downturn, forinstance, 98.5 percent of T. Rowe Price's 2 million planparticipants didn't touch their allocations.

Fidelity agreed that most investors haven'tmodified their plans during period of intense interest.

The rule of thumb for 401(k) plans during market volatility isto, in fact, do nothing.

As this best practices guide from T. Rowe Priceexplains, markets have enjoyed a 75-year stretch of increases.

People who keep their retirement money invested over the longhaul do better than those who try to predict downturns. During thefinancial crisis, for example, Fidelity found that those who didn'ttake money out of their plans saw 88 percent growth over thenext five years.

Savers who moved their assets out of equities in 2008 andremained that way for the next five years, a tiny minority ofFidelity clients, saw 15 percent growth over the period.

"It's really hard to time the market," said Chip Castille,BlackRock's chief retirement strategist. "And when you react torisky events what you're in effect doing is timing the market,that's a very hard thing to do for most individuals."

The good news is: Americans with 401(k) appear to have learnedthese lessons and tend to stick to the best practices.

Even during the financial crisis, only 1 percent of Fidelity'splan holders got completely out of equities. In any givenyear, on average, Fidelity's Thompson said only 10percent of plan holders will move money betweenfunds.

And yet, in seemingly dire times, we need something to assuageour financial anxieties.

Thompson believes that people compulsively check on theirdwindling 401(k) plans to feel comforted that nothingneeds to be done. "Most people are calling just for reassurance andconfidence," she said, "and making sure that, in fact, theyshouldn't do anything and stay the course."

Like with any tragedy, we want to take a clear look thedamage—and then we want someone to tell us it's all going to beOK.

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