May 17 (Reuters) - Several prominent investment management firms purchased shares in the first quarter of companies that plummeted when large banks sold them in a hurry amid the collapse of private investment firm Archegos Capital Management at the end March. Regulatory filings show that Soros Fund Management and hedge funds HG Vora Capital Management and Coatue Management entered positions in media stock ViacomCBS Inc after disclosing no holdings in the previous quarter.