Borsa Istanbul's Daily Shift: Top Gainers and Losers

Borsa Istanbul’s BIST 100 and BIST TUM indices edged up by 0.48 % to 10,532.65, only to retreat 0.72 % to 10,478.30 on October 20, 2026.

The Rise Behind the Numbers

■Turkcell: +5.2 % – 5G rollout boosting demand

■BİM Birleşik Mağazacılık: +4.8 % – Logistics efficiency and price advantage

■ASELSAN: +3.9 % – Defense contracts growth expectations

The Shadow of Decline

■Garanti Bank: –3.1 % – Unexpected credit portfolio dip

■Petkim: –2.7 % – Raw‑material price volatility

■Zorlu Energy: –2.5 % – Renewable‑energy project delays

Sectoral Echoes

■Telecommunications: +4.6 % – Strong growth and investment signals

■Retail: +3.5 % – Rising consumer confidence

■Financials: –2.8 % – Interest‑rate and regulatory uncertainty

Market Core Metrics

■Liquidity: 2.3 B TL trading volume, 1.9 B TL net buying

■Asset Diversification: Sector‑weighted, 35 % tech, 25 % finance

■Outlook: Year‑end forecast for BIST 100 at 10,800.00

As a portfolio manager, the day’s sharp swings underscore the value of a disciplined dividend‑yield focus and a strategic buyback perspective to anchor long‑term value creation.