Nvidia Corp.’s stock chart shows that, after the stock’s continued surge into record territory, it is now technically the most overbought it has been in six months — but that doesn’t mean the rally is over.In fact, some chart watchers believe the stock’s recent breakout marks the beginning of the next leg of the uptrend, which could propel the stock above the $600 level.Katie Stockton, technical analyst at Fairlead Strategies, said the breakout was a “bullish medium-term development,” as it resolved a four- ...