High-rolling investors have positioned themselves bearish on United Airlines Holdings (NASDAQ:UAL), and it’s important for retail traders to take note.\This activity came to our attention today through Benzinga’s tracking of publicly available options data. The identities of these investors are uncertain, but such a significant move in UAL often signals that someone has privileged information. Today, Benzinga’s options scanner spotted 11 options trades for United Airlines Holdings. This is not a typical pattern. The sentiment among these major traders is split, with 27% bullish and 72% bearish…