Corporate debt — legally senior to all preferred and common equity. Strategy has issued roughly $8B+ across 2027, 2028, 2029, 2030 and 2031 maturities, virtually all at 0% coupon: the return to noteholders comes entirely from the conversion option, not cash interest.

The most senior preferred series — ranks just below corporate debt. No equity upside (not convertible), so it prices and trades more like a bond: investors are underwriting Strategy's ability to keep paying a fixed 10% coupon, not the BTC price.

Designed to behave like a money-market instrument — a floating coupon that Strategy adjusts to keep the share price anchored near $100, rather than a fixed rate. Ranks below STRF, above STRK.

The middle tier: a lower fixed coupon than STRF/STRD in exchange for upside — if MSTR rallies far enough, converting to common is worth more than the preferred dividend stream.

Highest advertised coupon in the stack, but the trade-off is real: non-cumulative means if Strategy skips a payment, that money is gone, not accrued. Ranks just above MSTR common.

Last in line if the capital stack were ever unwound, but the only instrument with unlimited upside. Every other security in the stack exists to fund buying more Bitcoin without issuing more of this one at an unfavourable price.