While this was definitely the case from August through October 2017, alts overall are no longer actually downtrending when bitcoin pumps. Look at the charts here www.altindex.io. When bitcoin pumped in the beginning of the New Year, alts pumped massively (peaking briefly on Jan 5th). When Bitcoin recovered from Jan 12th to 21st, alts recovered as well. Even in the past 2-3 days with bitcoin pumping, the alts continue to climb.
The chart I'm referencing at www.altindex.io is the T&C 20 Index which is a market-cap index that includes approximately 20 highly traded medium to large altcoins (including stratis). I think it is the best way to track the altcoin market. Sometimes its easy to miss the forest for the trees when looking at specific coins.
Wow, may I borrow your time-machine please?