What is more valuable… holding STEEM or STEEM DOLLARS?

There is STEEM, STEEM POWER and STEEM DOLLARS.

STEEM just liquid, no interests, no appreciation in value. It even dilutes about 0.19% a day. Definitely you should not hold it, it only has transactive purpose. Buy it, sell it, convert it to STEEM POWER.

STEEM POWER power is for you if you want to be deeply invested in steem. It is not liquid, for example to convert all your STEEM POWER back to STEEM will take 2 years. But only holding STEEM POWER you can collect rewords that system will give you. If you vote for post, the more STEEM POWER you have, the bigger your reword for curating. System pays reword by inflation, for each STEEM created to pay rewords, 9 STEEM more created and goes to STEEM POWER holders. By voting and posting you will be payed from 10% of inflation, by just holding STEEM POWER you will be reworded from 90% of inflation.

STEEM DOLLARS is in the middle of these two. It has stability, its liquid. System pays you interest just for holding them. It's defensively better then USD.