This seems a plausible optimistic hypothesis for BA, a retracement to its longer-term support.
A consensus explanation for why BA is crashing isn't clear to me, other than fears of a trade war. But some are skeptical of that explanation. A simpler explanation is, look at the strong parabolic movement starting on Jan 4, 2018, the same movement seen across the market. Its magnitude of trend-deviation cries out for a retracement to trend. Right at the new year an exuberance of optimism raised prices across the market, so BA's drop may be a retracement to prior optimism hastened by fears of a trade war, etc.