Crude oil futures have rebounded after trading lower earlier in the day, with buyers defending a key cluster of technical support.The low reached $91.70, just above the 38.2% retracement of the rally from the July low to the September high at $91.60. The price also held above the rising 100-hour moving average at $91.36 and the 200-hour moving average at $90.86.That trifecta of support gives traders a clear area to define risk. Sellers would need to break below all three levels to shift the technical bias more firmly to the downside. Until then, buyers retain more control.Buyers reclaim $93.48. Yesterday’s high is next.The rebound has taken the price back above the top of a swing area at $93.48, with crude currently trading near $93.79. Staying above $93.48 would keep the immediate momentum tilted higher.The next target is yesterday’s high at $94.36. A break above that level would open the door toward the late-September highs near $96.50, followed by the swing area between $97.00 and $98.48.What would give sellers more control?A move back below $93.48 would weaken the rebound, but sellers would still need to work through the support cluster between $91.60 and $90.86.A break below that area would put Monday’s low near $89.60 in focus, followed by the September swing low at $88.72. Below those levels, traders would look toward the 50% midpoint of the July-to-September rally at $86.91, which was tested on October 6.For now, sellers had their shot near the retracement support and could not push through. Buyers have regained some momentum. The next challenge is to hold above $93.48 and extend through $94.36.Trading lesson: Use technical levels to define riskWhen a Fibonacci retracement and moving averages sit close together, they create a cluster of support. That gives traders a clear area to judge whether buyers are holding control or sellers are gaining ground.For crude oil, that area runs from $91.60 down to $90.86. Holding above it supports the bullish bias. Breaking below it—and staying below—would strengthen the sellers’ case.The lesson is to let the price action guide you. Support gives buyers a place to lean against and define risk, but it does not guarantee a bounce. Know what would prove your trade wrong before you enter. This article was written by Greg Michalowski at investinglive.com.