Huge numbers of Americans are leaving the workplace in a surprise second wave of the post-COVID retirement boom.

Why it matters: An aging country — combined with a booming stock market and a nudge from return-to-office policies — means more working stiffs are preparing to exit the stage.

What's happening: The U.S. has about 2.7 million more retirees than predicted, Bloomberg reports from a model designed by an economist at the Federal Reserve Bank of St. Louis.

• That number was 1.5 million six months ago — a more than 80% increase. Before the pandemic, there were often fewer retirees than expected.

The big picture: The pandemic fundamentally altered the labor force in ways that made the jobs market historically tight.

• Many people retired, while others dropped out of the labor market altogether.

Zoom in: Higher stock market returns and increasing asset values appear to be playing a role.

• For those nearing retirement, there's arguably no better time to start the golden years than during a bull market.
• The S&P 500 closed at a new record high on Thursday after a respectable earnings season.

Between the lines: The increasing number of 401(k) millionaires are outstripped by the sheer number of graying citizens who aren't prepared financially for retirement, especially as the social safety net frays.

• The 65-and-older cohort is set to soar by nearly 50% by 2050, with its share of the population rising from 17% to 23%, according to the Population Reference Bureau.
• Social Security is flirting with insolvency as millions of Baby Boomers retire — raising serious questions about whether those benefits will be available for Generation X and Millennials when they get set to call it quits.