This is true. Most spreadbetting companies will manipulate prices and take the other side of the trade or basically stack the odds against you. So if you spreadbet, take care they are one of the brokers I like because they are large, long-standing, stock market listed, and UK/US regulated ie have a reputation which has stood the test of time.
I prefer blind agency brokers which match buyers and sellers - so they cannot simply bet against you.
My brokers that I like: