The U.S. dollar saw a slightly different performance profile over the period. The dollar, which had been in a short-term downtrend ahead of the 2013 shutdown, briefly dipped for the first couple of days before rallying back strongly in the latter half of the government shutdown. Once a deal was announced, the dollar index sold off sharply, perhaps as a result of a fading "flight to quality" bid. Overall the greenback finished the entire two week period modestly lower, in-line with the dominant downtrend at the time.

On the whole, the 2013 government shutdown did not do little to interrupt the established trends in either the S&P 500 or the U.S. dollar. After an initial period of weakness, both assets rallied as a budget agreement grew more likely, though it's worth noting that the buck sold off once an agreement was reached.

Of course, it's impossible to say whether markets would follow the same path if we see a U.S. government shutdown this time around, but this analysis supports prioritizing a trend- and price-based outlook toward markets, regardless of the "news" grabbing all the headlines.