Every strategy can be good, but there's no strategy that works in long run, you need to change strategy and try to adapt to the current market conditions. I can't say that trading can be completely safe, but with some steps you can lower the risk. Greediness is the number one killer, with that part I agree, doesn't matter on strategy someone is using, greediness is a money eater! Another step to lower the risks is patience, to not make sudden actions, be patient and wait for your moment, bitcoin is volatile and if you miss a good moment for something be patient and wait for next good opportunity.