I was talking to my attorney, from the esteemed firm of Dewey, Cheetum and Howe, and he made the above remark in response to a financial statement that I had produced earlier. What did Bernie mean?
A "bucket shop" is an unethical business operation:
(Investopedia.com notes that the latter definition "comes from more than 50 years ago, when bucket shops would do trades all day long, throwing the tickets into a bucket. At the end of the day they would decide which accounts to award the winning and losing trades to.")
A "piker" is a small-time player, someone who operates cheaply and takes only small risks in a very cautious manner.
So, Bernie is saying that this place is a shady operation that caters to cheap, chintzy, risk-averse individuals and tries to continuously cheat them out of small amounts of money; they will throw in only an occasional small payoff to a customer to offset a part of the overall loss suffered, so as to keep him hooked on the possibility of getting a big payoff.