There are many foreseeable effects. Some of them will actually happen and others won't. Some of them are in direct contradiction with others. Some of them will

There are many foreseeable effects. Some of them will actually happen and others won't. Some of them are in direct contradiction with others. Some of them will result in a greater or lesser financial impact than expected. Beyond that there are unforeseen and unforeseeable impacts. Discounting all that, yes, I believe the market is reasonably efficient.