Short the Long Bond on the Shortest Day Ever 

Today will be the shortest day in history as Earth’s rotation unexpectedly speeds up – Daily Mail

A Celestial Signal from the Macro Gods?

Today, we’re taking a position against the long end of the Treasury curve—not just for fundamentals or flows—but because July 9, 2025 is, quite literally, the shortest day in recorded history. According to scientists, Earth will complete its full rotation 1.4 milliseconds faster than usual, thanks to a curious combination of gravitational dynamics, axial tilt, and the Moon’s peculiar position high above the equator.

This isn’t a random celestial hiccup. Earth’s rotational speed has been picking up since 2020, causing days to grow imperceptibly shorter. While we’re not feeling jetlagged just yet, timekeepers are. The International Earth Rotation Service (IERS) may soon introduce the world’s first negative leap second—a rare, almost philosophical correction that could wreak havoc on GPS systems, power grids, and yes, algorithmic trading clocks.

Back to Bonds
Markets love symmetry. They crave time-tested patterns. And yet here we are, staring at an auction calendar on a day when the very rhythm of the planet has gone rogue. On this backdrop, today’s U.S. Treasury auction feels like a cosmic stress test: will buyers (especially, foreign) show up? Or will the accelerated rotation be mirrored in higher yields and faster repricing?

The scientific backdrop offers poetic alignment:

• The Moon’s orbital path is tugging Earth off its usual timing, accelerating spin by fractions of milliseconds.
• Researchers like Duncan Agnew (Scripps) and Leonid Zotov (Moscow State) note that even the molten core is shifting momentum—something no one modeled into duration risk.
• Earth’s shape is subtly changing due to melting glaciers, redistributing mass like a nervous bond trader shifting from 10s to bills.

So we say this: on the shortest day ever measured, duration is too long. The bet? A lackluster auction. Weak coverage. Yields pushing higher in defiance of the calendar’s brevity. We’re short the bond, long the metaphor.

After all, when the planet itself starts front-running time, maybe it’s trying to tell the markets something. Watch the clock—and the yield curve.

Happy trading, and enjoy your slightly shorter spin around the axis today.