It was easy to miss, buried as it was under an avalanche of domestic political headlines, but investors just witnessed history.

As documented here on at least four occasions over the past several days, US small-caps outperformed big-caps and mega-cap tech by the most in nearly half a century in recent sessions.

That showing would’ve garnered above-the-fold coverage in the financial pages were it not for what I (aptly) described as “the most bizarre, extraordinary week for American politics in living memory.”

In his latest, Goldman’s David Kostin documented the four factors behind what he called — and this is verbatim, exclamation point and all — “Whiplash!”

The figure on the left, above, is just another version of a chart widely circulated in recent sessions. You can draw a similar picture using the Russell versus the Nasdaq 100, the equal-weighted S&P versus the cap-weighted gauge, and so on. Kostin called it “epic.”

Fed cuts are key for small-caps, Kostin wrote, noting that nearly a third Russell 2000 companies’ outstanding debt is floating-rate. “When the Fed eases, interest expense for these companies will fall, and analysts will raise their EPS estimates,” Goldman said. “Stocks typically rise when EPS revisions are positive.”

At the same time, there’s scant evidence to suggest the US economy’s at cliff’s edge. It’s true that growth appears to be decelerating meaningfully and that labor market readings look poised to soften, but the most recent retail sales release came with a very robust read on control group sales and generally speaking, a so-called “Wile E. Coyote” moment for the economy seems unlikely.

As long as the economy doesn’t downshift suddenly and dramatically, the benefits to small-caps from rate relief might offset any drag from slower growth an incrementally less pricing power. Or at least that’s the thinking among investors.

There’s a political element too. “Small-caps tend to be very sensitive to the US economic growth environment, and they strongly outperformed following Trump’s 2016 election,” Kostin wrote, adding that small-caps’ “are also more domestic-facing than large-caps and less vulnerable to tariffs.”

Finally, there’s the “catch-up” argument. The figure on the right, above, underscores the extent to which EPS growth for the leadership’s expected to slow while profit growth for the rest of corporate America’s seen accelerating, closely the gap.

Ultimately, Kostin sees some room for the rotation to continue. “The recent trend of small-cap outperformance will likely persist unless the macro environment changes substantially, or the mega-cap tech stocks report Q2 results that causes analysts to raise revenue forecasts for the next several quarters,” he wrote.