Watch For Clues in Other Markets.
It is very important to monitor the entire market even if you trade specific to one sector. Market correlations are very important to consider and evaluate as the entire markets works to one set of news stories. They may have a longer or shorter-term effect but what is good for a nations currency often spreads to equities, bonds and interest rates.
In 2008 when the markets were falling apart certain FX crosses were highly correlated with the S&P 500. AUD/JPY (Australian Dollar vs the Japanese Yen) highly correlated to the S&P 500, you might ask why? First, the correlation is most important, the reason, secondary it does not matter why, but you had to keep an eye on it as there were often very important signals monitoring one versus the other.
US Dollar vs Gold, Philly Semi-conductor index vs S&P 500, Ten Year note vs equities. All of these at different times in history have important correlation impacts on the broader market and given profitable signals in one market vs another or a completely different market opportunity.
Remember when Oil was over $100 analysts said when oil moved higher it would be a negative for equities as consumers would have less disposable income? Then in 2015 when oil was below $30 it was also supposed to be a negative as oil rigs were shutting down and many were out of work.
It is less important to know why a specific market are correlated but It is important to know what the market is focusing on and trade accordingly.