Disclaimer: The analyst who wrote this piece owns shares of Strategy (MSTR).

Over the past two weeks, Strategy (MSTR) has refrained from utilizing the at-the-market (ATM) equity program on its common shares to fund bitcoin BTC purchases, choosing instead to use the programs on its two perpetual preferred stocks.

The choice most likely reflects the narrowing premium between the company's share price and its multiple net asset value (mNAV) or, more colloquially, the difference between its market cap and the value of its bitcoin holdings, and allows Strategy to raise funds to buy more BTC without diluting shareholders' stakes in the company.

When the share price trades close to the underlying bitcoin asset value, issuing common shares via ATM becomes less attractive. Such offerings are typically only advantageous when executed at a meaningful premium.

Strategy funded its most recent 1,045 BTC purchase using proceeds from its two perpetual preferred stock ATMs: 59.18% from the STRK offering and 40.82% from the STRF one. These preferred stocks have demonstrated strong lifetime returns of 35% for STRK and 24% for STRF. This gives the company greater flexibility to continue accumulating bitcoin while preserving upside for common stock investors.

There's also an additional dynamic at play, according to analyst Jeff Walton. The effective dividend yields of STRK and STRF have steadily declined from about 10% even though the yield on the benchmark U.S. 10-year Treasury has remained relatively constant at 4.5%. That's because the dividend yield falls as the price of the stock increases, a bond-like behavior that makes the preferred shares more attractive in a stable rate environment.

Strategy is likely to reengage the ATM on its common stock if the share price rises significantly, particularly if it exceeds twice the mNAV, which would allow room for dilutive issuance at a premium. While the common stock ATM remains the primary mechanism to fund dividend obligations on the preferred shares, Strategy retains the option to use the preferred stock ATMs for this purpose as well, depending on market conditions.