There are three types of Market efficiency; weak, Semi-Strong and Strong. In theory, the market should be Strong, which means that all information is reflected in the price, and there is no inside information that gives anyone an edge. The price changes instantaneously the moment anything changes, and is based on all future cash flows discounted to Present Value.
In reality this is not the case, as financials and intentions are not always made public. In reality we are in a Semi-Strong Market, where Public information is included in the price (albeit not immediately) but not anything unknown to the public (unpublished financials).
Which is why the PPS is where it is and not where it could/should be.