A handle is the whole number part of a price quote. In a quote the handle could be $56, while the price quote for stock might be $56.25. The quote's handle eliminates the part of the price quote that is a decimal. In foreign exchange markets, the handle refers to the part of the price quote that appears in both the
bid and the offer for the currency. For example, if the EUR/USD currency pair has a bid of 1.4183 and an ask of 1.4185, the handle would be 1.41 - the part of the quote that is equal to both the bid and the ask. Also called big figure.
Read more: Handle Definition | Investopedia
https://www.investopedia.com/terms/h/handle.asp
In trading, the handle has two meanings. In most markets, it means the whole numbers involved in a price quote, without the decimals included. In forex, the handle refers to that part of the quote that appears in both numbers of the spread.
Both offer a faster way of referring to the price of an asset at a particular point in time. If a stock is trading at $46.24, its handle is just $46. If a currency pair can be bought for 1.6456 and sold for 1.6400, then its handle is 1.64.
Source:
https://www.ig.com/uk/glossary-trading-terms/handle-definition
Refer also: TICK, Point,
PIP