There's also a YC company, (https://secondmeasure.com/ https://secondmeasure.com/), that sells anonymized credit card data to hedgefunds so that the funds can d

There's also a YC company, (https://secondmeasure.com/ https://secondmeasure.com/), that sells anonymized credit card data to hedgefunds so that the funds can directly check the volume of trade happened at walmart, etc.