Why does stock data cost money?

I've been reading and many people say that all the low cost options are unreliable. And Yahoo and Google do not provide enough intraday data to have anything remotely close to resembling an amount necessary for backtesting. And I'm not going to spend thousands of dollars on data. I really feel like I wasted my money on amibroker because there is no reasonably priced data. It should be free.

 

So trade the free eod data from yahoo. You can for example use decades of GE data for backtesting (40 years of eod data > 10k data points).

 

Collecting, storing, cleaning, and maintaining the data costs money.

Would you do all that for the benefit of the ET crowd and provide it for free?

 

I came across Disktrading a couple years ago (http://disktrading.is99.com/disktrading/) ... they don't have historical data for stocks it seems, and they couldn't provide what I was looking for, but they certainly qualify as inexpensive.

 

Well, plenty of people post websites and blogs containing a treasure trove of information, as well as host servers for gaming and other services and maintain it all for free. I don't see the difference.

My main complaint, is that all the ones that I would find cheap enough, people lambaste as incorrect. It's one thing to have to pay for data, but paying for INCORRECT data?

 

http://www.crsp.com/

This is the most correct data out there. They spend lots of hours cleaning it up. I don't know the cost.

 

I asked CRSP a few years back... their US stocks database was $42K per annum if you got updates delivered monthly - about 40% less if you got it delivered annually.

 

I don't think anyone would be that generous. After all, there is a reason traders pay good money for stock data. It is to gain a big advantage while trading and they don't want to lose that advantage.

 

Everything costs money, nothing is free. It is either paid directly or through advertising.