Norwegian Cruise Line Holdings Ltd's (NYSE:NCLH) stock just flashed a signal traders rarely ignore — and it comes at an awkward moment. NCLH has now printed a Death Cross, with the 50-day moving average slipping below the 200-day, signaling that short-term momentum has overtaken the longer-term trend to the downside.Track NCLH stock here.The stock is already down about 18% year to date, with selling pressure intensifying over the past month. Yet the chart isn't collapsing outright — setting up a tense momen ...