Recent regulatory filings provide a snapshot of the investors with large stakes in the company who added or sold shares during the third quarter. The filings, in concert with the firm’s share price moves, shed some light on potential paper losses at different funds during the period, but may not capture all trades during the quarter. J.P. Morgan Chase & Co.’s asset management unit, T. Rowe Price Group Inc. and Fidelity Investments were among the 10 largest Valeant shareholders at the end of September, according to S&P Capital IQ. Other large shareholders at the time included hedge fund firm Paulson & Co. and GMO...