Hedge funds moved quickly to cover short positions on Friday which were undermined after a sharp rebound in US equities, according to a report by Bloomberg. Short interest in US exchange-traded funds had jumped 4.6% on Thursday — one of the biggest single-day increases this year — according to data from Goldman Sachs. Led by semiconductors and semiconductor equipment stocks, positions in single stocks were also trimmed, after the S&P had recorded its most dramatic intra-day reversal since April. Funds were then forced to close out these positions as stocks climbed on Friday, with strong showings from Big Tech contributing to a 1% gain in the S&P, the largest daily rise since May.