I think averaging down can be a very useful tool. In my opinion, a lot of the "don't ever average down" talk comes from traders in the futures market, which can be very unforgiving and in my opinion is a bad market to average down into. Quite a few traders trade by choosing "inflection points" on a stock/future, and if it goes past that point, the inflection point has failed and can be deemed "wrong", and losses should be cut, since the original purpose of the trade is no longer valid. But for other strategies, such as reversion to mean strategies, the further away price gets away from wherever you calculate it should revert to, the trade looks better and better, and averaging in is part of the strategy, since essentially you are trading against some kind of fair value calculation. That doesn't mean you average in whenever you feel like it, or that you shouldn't take a loss. To add more size to a position going against you, you have to be aware of the overall market environment, and if not hedged, perhaps have an opinion on the futures if in a non-market neutral stock, be aware of news, other stocks in sector, anything that would cause it to significantly deviate from where it "should" be, and also have an idea of its daily range, and what is normal, what constitutes a fat tail event, what your new average price will be after adding, your available leverage, and your exposure to this security relative to whatever positions you have on and your net long/short market portfolio exposure. Even doing all this, sometimes you will get smacked hard and take a huge loss. I think a lot of people get too big too fast when averaging on a position, and they generally get focused on that position only, and are unwilling to ever take a loss on it, leading to disaster. Averaging down responsibly can be done IMHO, just depends on the reason why, and some markets and strategies are suited better for it than others.