I agree. If you look at the bitcoin you can increase your bitcoin value instead of usd as of the moment so when the bitcoin price increases again you can earn a lot more money.
Ok.That might be right because many people think so.Bitcoin is really the most popular among other coins so they consider and accept that bitcoin is the best investment.But we must be realistic that quantitatively, other cheaper coins like eth, ripple and litecoin have bigger returns within certain time period recently.In that case, I consider that not only btc but other coins are good investment instrument.