ORLANDO, Florida, Jan 27 (Reuters) - World stocks and the S&P 500 hit new highs on Tuesday, boosted by a flood of strong U.S. earnings reports, while anxiety over U.S. President Donald Trump's policy direction sent safe-haven gold to fresh peaks and sank ​the dollar to a four-year low. More on that below. In my column today I look at why Japanese authorities might still unilaterally ‌intervene in the FX market to support the yen, even though the chances of joint action with the United States are probably ...