Definition - What does Blotter mean?
Blotter is a daily record of broker dealer transactions.
Testopedia explains Blotter
There are several yypes of blotters: receipt and delivery of securities; purchase and sale of securites; receipt and disbursement of cash. All blotters are considered records of original entry. They must be posted, i.e.: updated, no later than one business day after the event and copies must be kept for 6 years.