(Bloomberg) –Saudi Arabia’s main equity index fell the most in the Gulf on Sunday ahead of Saudi Aramco’s giant listing.

The Tadawul All Shares Index finished 0.8% lower, falling for the first time in six sessions. Al Rajhi Bank, the biggest listed lender in Riyadh by market capitalization, contributed the most to the decline, paring its 4.7% gain last week.

Investors are taking profit as Aramco’s IPO approaches, which many analysts have said may crowd out the market.

Last week the local banking index outperformed the main gauge, partly because lenders are expected to get a revenue jump by providing margin loans and brokerage services to customers buying Aramco shares. But the boost could be short-lived, analysts say.

Aramco garnered 73 billion Saudi riyals ($19.5 billion) in orders for its shares in the first five days of its offering, Samba Capital and Investment Management Company said last week. The IPO may be the world’s largest if the stock is sold at the top end of the range, which would give the company a valuation of $1.7 trillion. The end of the subscription period for retail investors is Nov. 28, with the final offer price to be disclosed on Nov. 5, the company said last week.

HIGHLIGHTS:
The MSCI Emerging Markets Index finished the five days through Nov. 22 little changed, and an index tracking currencies from developing countries fell 0.2%

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MIDDLE EASTERN MARKETS:

• Al Rajhi Bank declines 1.1%, trimming gains this month to 6.3%
• Also in Riyadh, Arabian Centres climbs 2.6%, extending gains of 3.7% last week
• Stock should attract ~$21m in passive inflows as FTSE Russell adds it to EM benchmarks next month, according to estimates by EFG-Hermes
• NOTE: Stock was rated new buy at Arqaam Capital last week, PT 35 riyals
• Gauges gain between 0.1% and 0.4% in Dubai, Kuwait and Israel while benchmarks in Abu Dhabi, Bahrain, Oman, Qatar and Egypt lose as much as 0.3%