[sova]

I don't know! I'm wondering! Because weak-form efficient means something different than strong efficiency, which is what you say when the market perfectly incorporates all data. Just out of curiosity, if the data doesn't go into the market, where does it go? Strong econ minds believe that prices do incorporate all the data necessary for valuation

[Dylan16807]

Sometimes data gets lost. People are making the decisions, and people are sloppy and lossy.

Weak and strong are just about which data is incorporated. Neither one addresses the fact that no entity interacting with a market is infallible.