JPMorgan analyst Tami Zakaria downgraded Party City to Neutral from Overweight and lowered her price target for the shares to $12 from $14. The helium supply shortage is now expected to persist throughout 2019, which is a "step change from management's earlier commentary that the situation was likely to improve with the opening of new refining facilities, Zakaria tells investors in a research note. The company is currently at 60%-70% helium allocation versus 80%-85% normally and expects the shortfall to continue at these levels in 2019, the analyst points out. Further, Zakaria sees risk to Party City's back half-weighted ~1% comp guidance for 2019 "that will likely weigh on the stock until disproved."