According to a Keyrock research report, Strategy's $1.45 billion preferred-share buyback program supported a substantial share of trading in its variable-rate preferred stock, STRC. The company's repurchases accounted for over 20% of STRC's weekly trading volume during almost every week of September, reaching about 28% the week of Sept. 8 before falling to just under 20% in early October. As of Oct. 4, Strategy had spent approximately $1.45 billion of its $2 billion repurchase authorization, with $547.2 million remaining. The findings raise questions about STRC's market liquidity and its sustainability without continued issuer intervention.