A widespread decline in technology equities pressured US equities on Wall Street Friday, concluding the market’s most challenging week since late June. The S&P 500 decreased 1.1%. Its approximate 2% decline for the week erased advances from the prior week, when it achieved a record high. The Nasdaq composite, which carries a significant weighting in technology stocks, shed 2.1% and registered its initial weekly decline in five weeks and its steepest since June. The Dow Jones Industrial Average finished down 0.3%.