Short interest in Calamos S&P 500 Structured Alt Protection ETF September (ARCA:CPST) increased during the last reporting period, rising from 3.90K to 11.69K. This put -% of the company's publicly available shares short.

Based on the recent average volume of 6.83K shares traded per day, it would take 1.71 day(s) for holders of this short interest to close out their positions without sending the stock sharply higher.