In 2015, the overall market lost almost 1%... but the Consumer Discretionary sector (that's things like cars... and clothes.... and luxury goods) went up 10%:
Same thing in 2018... the overall market went down 6%, but if you focused on the winning sector – Health Care – you could have made 6%:
And that story is playing out all over again this year...
The overall market has suffered a brutal 20% sell off... but the energy sector is up more than 30%:
If you looked at almost any investment portfolio, I'd bet you'd see that the biggest winners happened during years when its underlying sector was on a tear.