NEW YORK (Reuters) - Money managers rebalancing their portfolios to boost equity exposure into the end of the quarter may support the nascent stock rally that has followed the steep coronavirus-fuelled market drop.With the S&P 500 having lost around a third of its value in the recent selloff, investors may need to step up their equity purchases and sell bonds in order to maintain allocation targets. A portfolio that had stock allocations at 60% and bond allocations at 40% in mid-February may now..