This company's stock rallied strongly on important news, but has since started to cool off as the hard work begins.Opendoor Technologies (OPEN 2.50%) stock has risen approximately 263% over the past year, largely driven by investor reaction to a change in the CEO suite. However, the stock has fallen nearly 43% from its 52-week high. Is this an opportunity for investors who missed the original rally, or is it a recognition among investors that the changes being contemplated involve material risk?To understan ...