Investment Firm Files Finra Arbitration Demand Against Morgan Stanley

An investor accused Morgan Stanley of leaking information about a large sale of shares of Palantir Technologies Inc., saddling it with millions of dollars in losses.

Morgan Stanley is at the center of a broad federal investigation into whether Wall Street banks told favored clients about pending sales, known as block trades, that they were hired to carry out quietly. The investor, Disruptive Technology Solutions LLC, and affiliated funds on Monday filed a demand for arbitration against the bank with the Financial Industry Regulatory Authority, a copy of which was viewed by The Wall Street Journal.