Bitcoin is not backed by any physical asset like Gold nor by any fiat currency. It makes me wonder if I should invest/trade in Bitcoin or not?
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In simple terms, no. But you could say that about any currency these days because the "gold standard" was dropped decades ago and it was quite a big failure because the real gold supply didn't give governments enough flexibility. The price that Bitcoin is trading at in any given point in time is the collective evaluation of it's worth - if lots of people go to sell, the price drops until it hits the floor of buyers who will sustain it at a certain level. It's got less interference from central banks to worry about in comparison with a fiat currency, but the value of it can be shattered at any moment through regulations put into place that could effect cryptocurrency owners in certain jurisdictions (i.e. Europe and North America).