LONDON, May 20 (Reuters) - Hedge funds stuck to their holdings in companies with strong fundamentals in April, particularly technology and semiconductor stocks, according to a report on Wednesday from data platform Hazeltree, in a month when the S&P 500 jumped over 10%. 

Here are the details about hedge fund positioning in April:  

-- Among mega-cap stocks, Meta and Amazon.com ( AMZN ) experienced more than a 5% month-over-month increase in the number of funds holding long positions, Hazeltree said

-- Nvidia ( NVDA ) experienced a 4.5% decline, but remained a favourite long in the semiconductor sector

-- The share of companies in the Philadelphia Semiconductor Index in which hedge funds hold net long positions rose to 57% in April from 53% in March

-- Crowding in the U.S. semiconductor sector remained most pronounced on the long side in Nvidia ( NVDA ), followed by Broadcom ( AVGO ) and Lam Research ( LRCX )

-- On the short side, ON Semiconductor was the most crowded name, followed by Microchip Technology ( MCHP ) and Monolithic Power Systems ( MPWR )