Influence of index on stocks ?

Hi Pat, for couple of weeks we've seen NASDAQ index outperform S&P index (NYSE). So, when I want to pick a stock from keylist, will the exchange (index) play a role a stock belongs to ? For example, shall a NASDAQ stock be preferred over a NYSE stock now or does it not matter at all ?  Thanks in advance for your feedback. As always looking forward to hearing your opinion. Best Regards, TJ