Britain’s biggest charity, the Wellcome Trust, has amassed a near-£4bn war chest of cash amid fears of a stock market meltdown. The endowment fund, best known for operating the Wellcome Collection museum in London, said it was keeping about £3.7bn on the sidelines as “dry powder” in the hope of buying cheap stocks if markets tanked. It added that with stock markets at “all-time highs”, it felt that keeping cash on hand made sense, given stocks were too expensive to buy. The charity also said it had alr ...