Hi guys, I'm new to trading and I can't seem to find anyone discussing this topic in detail, so please help me understand this:

The bid/ask spreads for most major stocks (eg. Apple) are about 0.08%. So, if I were to buy Apple stocks, my position would be -0.08% right from the start. Let's say I were to close my position a day later, I would essentially have to pay another "fee" of 0.08%.

Basically, for each trade I execute, I'd have lost 0.16%. Is this right? Does this mean that if I were to execute 100 trades a year, that would amount to a whopping 16% and I'd have to beat that in order to even see any profits at all?

Do institutional investors, unlike retail investors, have any advantage in terms of the bid/ask spread that they'd have to pay?