InvisibleHand’s popularity has been putting a lot of strain on our servers. As a result there have been a few brief outages today during which US users will not have received price notifications. Our server gurus are working on the problem and normal service should be resumed very soon.
UK users are not affected.
In the mean time, please accept our apologies for any inconvenience caused.
UPDATE: The problem has been fixed. Everything should now be working as normal.