Riyadh: Shares in Saudi Arabia, the Arab world’s biggest stock market, climbed to their highest since late May on valuations and optimism in the US.

Etihad Etisalat Co., a Saudi Arabian telecommunications operator, had its biggest gain since April 1. Saudi British Bank reached its highest close in more than a month while Arab National Bank jumped the most in a week.

The Tadawul All Share Index gained 0.5 percent to 6,987.06, the highest since May 29, at the close in Riyadh. The measure has risen 8.9 percent this year. US stocks rose for the fifth week, giving the Standard & Poor’s 500 Index the longest rally since March, amid better-than-expected earnings and optimism that global central banks will take actions to stimulate growth.

“Usually around this time, end of Ramadan, investors lose interest and tend to book profit ahead of the holidays,” Asim Bukhtiar, head of research at Riyad Capital, said in a phone interview. “This year, valuations for banks and telecoms are quite attractive and optimism in the US about a recovery is helping lift stocks here.”

Etihad Etisalat gained 2.3 percent to 67.5 riyals. Saudi British Bank, 40 percent owned by HSBC Holdings Plc, rose 2.1 percent to 33.7 riyals. Arab National Bank added 1.7 percent to 29.5 riyals.

Saudi Arabia’s stock exchange is the only Persian Gulf bourse operating on Saturdays.