As a government shutdown drags on, markets are hard at work, dazzling investors on all fronts — from fresh S&P 500

SPX and Nasdaq COMP highs, to a rally for gold that’s about to take it to $4,000 an ounce.

Gold’s GC00 surge has a lot further to go, say Goldman Sachs analysts, who now predict the metal could trade near $5,000 an ounce by the end of next year.