Bucket Shop
You may think a bucket shop is just somewhere you buy cheap airline tickets. It's originally an American expression for a gambling den and in stockmarket terms that's something much less palatable.
A bucket shop, also sometimes called a boiler room, is a share-broking business run by somebody who is not a member of the stock exchange and is likely to be an out-and-out criminal.
It exists to push worthless or even non-existent shares to unsuspecting mug punters (the public). These companies will invariabley fail or fail to fulfil their claimed potential. The Internet is a fertile ground for such conmen (and conwomen)
Avoid at all costs!