1. retirement accounts are not all 401 K.
2. 401K can be all cash or bonds too
3. retirement accounts can be regular IRA, Rollover IRA, Roth IRA, 401K, 403B, and many many others
4. I do not know all, neither do you.
as to HT "是牛是熊调查“, that is just for fun。many HTers did not participate, include you or cobra. the ones who participate do not necessary represent the HT statistics.