Financial Dictionary

On balance volume is a running total that adds volume on up days and subtracts it on down days. A rising line suggests buying pressure is supporting the price.

A one cancels the other order links two orders so that when one fills, the other is cancelled automatically. It is often used to set a breakout entry in both directions.

OPEC+ is the group of oil producing countries in the Organization of the Petroleum Exporting Countries plus allied producers such as Russia. Its decisions on output targets are a major driver of oil prices.

Open interest is the total number of futures or options contracts that are still open. Rising open interest alongside a price move suggests new money is backing the trend.

An open position is a trade that has been entered but not yet closed. Its profit or loss changes with the market until it is closed.

The opening price is the first price at which an asset trades when a session begins. Gaps between the opening price and the previous close often reflect news overnight.

An order book is a live list of buy and sell orders for an asset, organised by price. It shows where demand and supply sit.

Order execution is the process of filling a trade once an order is placed. Speed and price matter, since delays or thin markets can lead to slippage.

An order fill is the completed execution of an order at a given price. An order can be filled in full, filled in part or left unfilled.

Order flow is the stream of buy and sell orders reaching the market. Order flow traders study it to judge which side is in control.

An oscillator is an indicator that moves between set levels or around a central line, such as RSI or the stochastic oscillator. Oscillators help spot overbought and oversold conditions.

Overbought describes a market that has risen so far, so fast, that it may be due a pullback, often signalled by an indicator such as RSI above 70. Strong trends can stay overbought for long periods.

Overnight funding is a charge or credit applied to leveraged positions held open past the daily cut off time. It reflects the interest rate on the borrowed amount, plus or minus the provider's fee.

Oversold describes a market that has fallen so far, so fast, that it may be due a bounce, often signalled by an indicator such as RSI below 30. Strong downtrends can stay oversold for long periods.

Overtrading means placing too many trades or using positions that are too large, often after losses or out of boredom. It raises costs and risk.