I was thinking in the better periodicity for my investing, and did a small excel to back up my numbers, it might be useful for someone else.

So, I get $2500 savings every month for investment purposes, initially they go to a savings account that gives me 4%, or 5% if I don't withdraw any cash. Doing a trade, due to this penalty and some forex fees costs me $50, or $35 if the trade is $10000 or more. I'm assuming a generous 9.6% return of invested assets.

If I do monthly investments the savings penalty, forex charges and trade fees work out to cancel any compounded interest, and after one year of investing I have a $6 loss, but after two years it gets better and I get a $1460 profit.

Bimonthly investments are a $270 profit for the first year, $2027 for the second.

Quarterly investments are a $378 profit for the first year, $2248 for the second.

After four years, the stash difference between the best and the worst of my options is 1%, so choosing the right investment period adds a yearly 0.25% to my stash, I'd say that's significant enough to spend 30 minutes playing with a spreadsheet.