The investors who are banking on stock markets for hefty returns beware. According to US-based investment banker Mack Rossoff, if Republican presidential candidate Donald Trump wins, stock markets will see their indices nosedive, at least initially. Speaking to NDTV's Vikram Chandra on The Big Fight, Mr Rossoff had a word of caution for investors as he believes Trump's win will push major stock markets down by 10-15%.