Mentioned in this article…

• van Binsbergen, Diamond, Grotteria: Risk-Free Interest Rates
• CME Group: Index Options Box Spreads as Financing Tool
• FRBNY: Options for Calculating Risk‑Free Rates
• Alpha Architect: Box Spreads: An Alternative to Treasury Bills?
• OCC: Box Spreads: Exchange-listed Options Strategies
• CME Group: Using financial Crude Oil options as a cash management tool
• r/wallstreetbets: The Legend Of 1R0NYMAN

Why care about box spreads?

Lots of investment products are built on top of the box spread, and more are coming.

The most famous is probably BOXX, the ETF (~$8 billion AUM, as of Sept 2025).

More BOXX-like ETFs are en route.

And borrowing/lending products like SyntheticFi, Vest, Arin’s Yield Hawk are already in market, all powered by the box spread.

Then there are rumored products, which I’ll just tease, including:

1. The listed variable prepaid forward (box + collar + portfolio margin loan)
2. The (admittedly speculative) box-powered tax-aware long/short separately managed account

I’m sure people are drawing on napkins this very moment, scheming about ways to disintermediate traditional borrowing and lending using the box spread.

So what?

New products launch and flop all the time. Is a productized box spread really that disruptive?