S&P 500 stock index futures sank further on Monday and global equity markets declined as investors reassessed stock valuations following a six-month run-up.

Futures suggested that Wall Street would open down about 1 percent or more, with crude oil futures down 2.6 percent to $70.13 a barrel and spot gold prices declining from above $1,000 an ounce.

A resurgent U.S. dollar sparked a pullback in shares of commodity companies, including energy and miners.

S&P 500 futures dipped 8.20 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures were off 60 points, while Nasdaq 100 futures dipped 11 points.

(Reporting by Ellis Mnyandu; editing by Padraic Cassidy)