I didn't pay much attention to most of the alts during the past 2 weeks (or rather, a week from the middle of May) but I also noticed Doge bucking this trend. It had always more or less kept trajectory with BTC in terms of fiat value, but while BTC was climbing to new ATHs, Doge was not only doing the same, but increasing in BTC value as well. I am now finding out that many alts rose in values greater than that of Bitcoin (percentage-wise).

I have theories but no evidence about why this is happening. Influx of new crypto users is the only reasonably sound answer, I'd say.