The price of WTI Crude Oil is identified as a key indicator for the end of the business cycle, with historical data suggesting that price spikes often precede economic downturns. The provided chart shows WTI Crude Oil trading at approximately $98.61, with a projected vertical price movement indicated by a green bar. The author suggests that rising geopolitical conflict could trigger a move higher in oil, signaling the "beginning of the end" for the current cycle.