Oats (ZO) have just put in the biggest rally since early 2014, which is when the former uptrend ended.
Following an extended downtrend, prior rallies can be used to gauge when something has changed. Over the last two years, rallies within the downtrend were 17.29% to 20.54% (on a closing basis). The October rally has seen the price jump 26.38% on a closing basis. The rally has eclipsed the April and June highs, signalling the long-term bottom in oats may be in place.
Buying after the price has already run this far isn't a prudent trade though. Prices always move in oscillating waves, so a better buy point will come on a pullback. If this is a first wave higher in an uptrend, then it will typically be followed by a deep retracement of approximately 70% of the advance. That would indicate a buy price around the 185 region. If the price pulls back and consolidates in that region, then buy a breakout above the consolidation with a stop loss below the consolidation. Alternatively, if just putting out a buy order in the 185 region, then a stop loss would need to be down around the former low of 171, which is much more risk on the trade.
185 may seem like a ways off right now, but trading is just as much about learning to sit on one's hands as it is about making trades.
Figure 1. Oats Continuous Daily Chart
If the pullback develops, then the price is expected to move back above 220, and over the longer-term could trade above 300. Oats traded nearly entirely above 300 from 2011 through to the end of 2014.