Methodology

Sector aggregates

Per-sector change percentages are market-cap weighted: each constituent's daily move is weighted by its total market capitalization (shares outstanding × latest close). Large stocks move the sector more than small ones, in proportion to their size.

sector_change_pct = Σ(stockᵢ.change_pct × market_capᵢ) ÷ Σ(market_capᵢ)

Daily change

Daily change is computed against the previous trading day's close, adjusted for cash dividends and splits. On an ex-dividend day a stock's dividend has been backed out of the previous close, so the calculation reflects the real economic move rather than a false drop equal to the dividend amount.

Headline indices

Headline indices (TASI for Saudi, ADX General for Abu Dhabi, QE Index for Qatar) are sourced from Twelve Data. Index values may lag intraday by 15–20 minutes and reflect price returns only — they do not reinvest dividends. Sector aggregates are independent of the index: they are computed from the price moves of constituent stocks, not from the index level.

Data health and gray-out

Sectors with fewer than 50% of their constituents reporting fresh prices on the current trading day are marked “data incomplete” and rendered in a muted state instead of an aggregate. The tooltip on a grayed-out tile lists the specific constituents that have not reported. This avoids publishing a sector number computed from an unrepresentative sample.

Halted stocks

Stocks halted for the day contribute 0% to their sector but keep their last-known float market cap in the denominator. This is the “stay-in” treatment: it prevents the denominator from shrinking and biasing the aggregate when a heavyweight stops trading.