The fiat value of bitcoin doesn't really matter when trading alts in the current market. Always comparing vs fiat was one of the mistakes I made when first getting into this. Trade alts to increase your bitcoin holdings, because bitcoin will always, eventually, return to its ATH (if not higher) if you can wait a few weeks, or months at most. So you can use bitcoin's ATH to calculate the medium-term value of your holdings when you need an emotional boost.