If you buy or sell shares using cash, you may only be able to take 4-5 concurrent positions before you run out of cash. If this is the case, you will not be able to take on any new positions until you exit your existing positions (i.e. their hit target price or stop loss).
For example, your starting capital is $10,000
Each trade requires you to buy $2,500 worth of shares. With 4 open trades, you will use up the entire $10,000 of cash from your account. Note however, that because of your stop loss, each trade only represents a 1% risk of your capital (i.e. $100 risk per trade)
If you use a margin account (broker usually allows you to buy up to 2X your available cash) or if you use CFDs (contract for differences) to buy/sell the underlying stocks, you will be able to easily take on multiple positions and all the trade alerts.
* CFDs are not available for US citizens.