Fat 401(k) accounts are turning into an accelerant fueling a wave of retirements, as one of history’s greatest bull markets finishes its 12th year. Since the pandemic started, the rate of retirements has jumped an estimated 75% and is running at a rate of about 3.5 million annually. That compares to about two million Americans a year in 2018 and 2019.

What could conceivably go wrong with this picture? Near-bubble prices in markets for stocks, bonds and housing for starters. Some noted observers, like Jeremy Grantham of GMO, have labelled this confluence as an unprecedented “trifecta” of bubbles.

The bond market is set up for a bear market after the Federal Reserve recently said it would raise the Fed funds rate three times in 2022. Evidence on how equities perform under these circumstances is more nuanced but muted expectations are in order.

But why worry? So far the bond market appears unfazed by the current bout of inflation or the prospect of higher interest rates. Yet as anyone who remembers the 2008 housing bubble can attest, the bond market has been wrong before.

Since the current bull market began in 2009, the S&P 500 has produced annualized returns exceeding 16% with dividends reinvested. As retirement authority Wade Pfau of The American College notes, inflated asset prices could be discouraging some Americans from taking a realistic look at future returns.

Early evidence, including studies by the St. Louis Fed, indicates that these recent retirees have been tilted toward younger baby boomers in their late fifties and early sixties. Some are not simply seduced by swollen portfolios but also frustrated by a host of problems arising from life under Covid.

Whatever their motivation, Pfau says they’d be well advised to lock in some of their gains in the equity market. Several advisors I spoke to said that’s the message they are delivering to first-time prospects who enter their offices and are about to pull the retirement trigger.

Many of these younger retiring boomers are acutely aware that they can access their tax-exempt 401(k) plans and IRAs once they reach 59½. But whether they have factored in the cost of paying for their own health insurance remains unclear. And whether they have planned to avoid the biggest mistake most early retirees make—taking Social Security early—is also a question mark.

The Great Financial Crisis of 2007-2009 sent millions of baby boomers into involuntary retirement and many had no choice but to take Social Security early as their only life raft. Over the following decade before 2020, the fastest-growing demographic in the workforce were people over 65, some of whom were forced to work on terms dictated by employers.

This time around, things are juxtaposed. Workers were jettisoned in nasty restructurings 12 years ago; today they are leaving voluntarily. More than most Americans, their savings levels look impressive.

But savings behavior for lots of Americans has improved dramatically since Covid-19 struck in March 2020. It’s doubtful, however, that Americans will continue to save like the Japanese. Many favorite spending outlets either were locked down or compromised, and eventually they’ll reopen. Early indicators are that booming retail sales this past Christmas could be a harbinger of things to come in 2022.

How this all plays out remains to be seen. Most financially literate, longtime clients of financial advisors shouldn’t see their retirements in jeopardy if they decide to exit the workforce a year or two earlier than planned. After all, any sound financial plan has built-in guardrails for the unexpected.

But conversations with financial advisors reveals that their clients aren’t the ones deciding in the last year to leave their employer—unless it was in the plan.

For the current cohort of retirees, there may be one saving grace. The labor market is running out of workers and employers are the ones pounding the pavement struggling to fill jobs. If participants in the Great Resignation conclude they have opted to retire too soon, it may be a lot easier to re-enter the labor force in 2022 or 2023 than it was 12 years ago.