 Jana Partners Trades, Portfolio, a New York-based firm, disclosed in a regulatory filing that its top trades during the first quarter included a boost to its position in Zendesk Inc. ZEN , Financial, the closure of its holdings of Macys Inc. M , Financial and LivePerson Inc. LPSN , Financial, and reductions to its holdings of Mercury Systems Inc. MRCY , Financial and the SP 500 Trust ETF SPY , Financial. 