Short interest in State Street SPDR Portfolio Mortgage Backed Bond ETF (ARCA:SPMB) increased during the last reporting period, rising from 240.26K to 416.56K. This put -% of the company's publicly available shares short.

Based on the recent average volume of 1.10M shares traded per day, it would take 1 day(s) for holders of this short interest to close out their positions without sending the stock sharply higher.