Handle invalid tickers provided by the API

[DerekMelchin]

The QuiverQuant API returns some invalid tickers

Here are all of the ones we found

(gld => 20210104
(tpgy => 20210226
.sox => 20220810
`mcd => 20250428
aapl) => 20210126
csco` => 20250515
bac` => 20220509
c) => 20210405
gm) => 20210212
kohl's => 20220119  (KSS)
nee_pr => 20240214, 20240415  (NEE)
poahy) => 20210416 (POAHY)
vnt) => 20210326