Stefani Reynolds/BloombergA recent Supreme Court ruling may slow down President-elect Donald Trump's deregulation plans.The overturning of the Chevron doctrine in June limits federal agencies' power, complicating deregulation efforts.Deregulation delays could disappoint investors who have been pricing in less red tape since Trump's win. A recent Supreme Court decision could hinder one of the stock market's biggest reasons for rallying around Donald Trump's coming second term in office.