Yes in terms of revenue derived from their assets under...

Yes in terms of revenue derived from their assets under management. Think of it like this;
Hypothetically BTC goes from 50k to 100k in a month.
If the fund is now valued at 100m under management, 15% is made in performance fees totalling 15m in revenue over that period.
However now assume that BTC drops from 100K to 10K the following month. DCC make $0 in performance fees. Then BTC rallies from 10k to 50k the following month.Management continue to make 15% on the gain(even though they have previously charged fees.)
So in this instance funds under management is 50m. Its baseline was 10k and rallied +40k so they remake 15% on the 40m fund increase (+ 6m in performance fees)
The following month BTC goes back to it's ATH and revisits 100k. Fund makes another 15m in performance fees.
For the period that BTC rallied and retreated the fund made a total of 36m out of a 100m asset fund. That's how fund managers make a fortune. In this example DCC are better off by 21m because of the price fluctuations as opposed to the 15m they make if BTC had only gone up.