Strategy stock was sinking on Friday despite a bump in the price of Bitcoin. It turns out that stock indexes may matter more than cryptocurrency prices right now.

Strategy stock was down 3.5% in premarket trading on Friday while the price of Bitcoin was up more than 1% over the past 24 hours to around $82,050.

Strategy is one of the world's major Bitcoin "whales," or large holders of crypto, with the company owning 848,250 tokens of the leading digital asset. Strategy's transformation from a business analytics company to a crypto pure-play based on its vast Bitcoin holdings has, ultimately, been good for the stock, which has more than doubled in five years of roller-coaster crypto prices.

But developments on Friday show that crypto prices aren't the only thing that matter to investors.

MSCI, the global provider of financial market indexes, is proceeding with a decision that would lead to the exclusion of Strategy from its Global Investable Market Indexes (GIMI).

It comes down to an eligibility test for index inclusion that would keep out "non-operating" companies -- those that essentially have no business functions beyond holding an asset, such as Bitcoin.

While MSCI currently looks to be proceeding with the update, Strategy is lobbying against the change, which could be reversed by Nov. 11, but would otherwise go into effect as of December 1.

"We believe the proposal is misguided," Strategy said in a statement on Friday.

"The proposal is a pretext for targeting Digital Asset Treasury Companies," Strategy said. "MSCI's 'operating' and 'non-operating' terminology is undefined, has no basis in U.S. GAAP, IFRS, or any recognized legal framework, and appears designed to reach a predetermined outcome."

Strategy alleged that the proposed deletion of Strategy from MSCI indexes "conflicts with established accounting and securities-law principles," and improperly "injects MSCI's own policy judgments into index construction."

The question remains just how much exclusion from MSCI indexes would affect Strategy stock by keeping out index buyers who end up as passive owners of the company's shares. Strategy said that funds tracking MSCI GIMI indexes hold only 3.1% of Strategy's shares outstanding.

Nevertheless, the turbulence in Strategy stock is a reminder to investors that even Bitcoin pure-plays are not always just that -- and when you're a public company, you can't outrun stock-market machinations.