Warren Buffett likes 50% Retracements

I was researching the holdings of XLF to prepare for Sector Rotation into Financial which I think is due shortly and the top holding in that ETF is BRK.B . While analyzing the chart I find that there were two distinct opportunities at major 50% Retracement Levels on 1/24/2022 and 2/24/2022. These are quite excellent holds of my key principle levels and a testament to the versatility of this one simple analysis.