An idiomatic term for a market holiday- that is, where all market activity comes to a halt for a day or more, and resumes the next day. This brings volume of commercial activity to zero on that specific day (s) and would temporarily prevent the market mechanism, as both buyers and sellers do not interact for a while until trading resumes after holiday. For a stock exchange, it denotes a non-trading day on the exchange.
Valium is a brand name for diazepam, a pharmaceutical drug that causes inactivity and drowsiness.
It is also known as valium holiday.
