Foreign investors increased their holdings in Greek stocks last month to 47.2 percent of the market’s total capitalization, from 46.8 percent in March, as turnover on the bourse shot up more than 50 percent, according to data released yesterday. Foreign investors, who held 50.5 percent of the capitalization in April last year, had been cutting their exposure to Greece stocks in recent months as the crisis deepens across Europe and the Balkans. Hellenic Exchanges, the holding group that operates the Athens stock and derivatives exchanges, said in a statement that Greek investors in April had trimmed positions in stocks to 51.7 percent of total stocks from 52.2 percent in the previous month. The bourse’s turnover in April was 55 percent higher than in March, rising to 3.67 billion euros from 2.37 billion euros. The Athens Exchange’s benchmark general index gained nearly 22 percent in the month of April, Hellenic Exchanges added.