Stocks lost ground Friday ahead of the weekend amid weakness in megacaps and caution before major news next week plus some soft economic reports. The Dow Jones industrial average and the S&P 500 both slipped 0.3 percent and the Nasdaq lost 0.5 percent. US bond yields, the dollar and oil prices all declined.

Growth concerns were rekindled by softer than expected consumer sentiment and S&P PMI services. Selling flowed from caution headed into the weekend given the prospect of more unexpected news from the incoming Trump administration and ahead of the Federal Reserve's policy announcement on Wednesday plus key reports on GDP and inflation.

Megacaps saw declines to weigh on the major averages. Nvidia was a notable decliner. Other favorities losing ground included Microsoft, Apple, Amazon and Netflix after recent gains. Among sectors, best were consumer staples, communications services, real estate and utilities. Lagging were information technology, industrials, energy and consumer discretionary.

Market Reflections track market reaction to the trading day's major events. Economic data, policymaker speeches, and company news are featured in this report as well as key indexes and financial instruments.

Understanding why markets respond as they do is fundamental for an investor. Market Reflections help explain how the day's events, news, and data impact the outlook for the economy and for market prices.