Key TakeawaysBoeing shares could remain on radar screens Tuesday after the embattled plane maker upsized a share offering announced earlier yesterday in a bid to shore up its finances.The stock recently rallied from the lower trendline of a falling wedge pattern but ran into resistance around the 50-day moving average, indicating underlying selling pressure.Investors should monitor key support levels on Boeing's chart around $146 and$121, while also eyeing resistance areas near $192,$234, and $268. Boeing ...