I can assure you that the majority or even all of us would answer 50% - 90% for bitcoin, mine is 80% bitcoin and 20% alts. Holding the most established coin is definitely the safest to place your investment to avoid losses. I also hold a good number of established altcoins that I usually sell when there's 20% + profit, and then buy more bitcoin. A few would always argue the opposite and I guess day trading works for them, but not for me tho; just too risky.