if you make or lose money hand over fist, you make or lose large amounts of it very quickly.

Business was good and we were making money hand over fist.

• keep someone on a short leash
• keep someone on a tight leash
• keep someone on the edge of seat
• keep someone on the edge of their seat
• keep someone on their toes
• keep someone on toes
• keep someone posted
• keep someone sweet
• keep someone up
• keep someone up to date
• keep something at arm's length
• keep something at bay
• keep something dark
• keep something down
• keep something from
• keep something from you
• keep something in check
• keep something in mind
• keep something to
• keep something to yourself
• keep something under hat
• keep something under wraps
• keep something under your hat
• keep something up to date
• keep sweet