Two persons buying the same stock through different brokers will have their trades handled separately. Even though the transactions occur simultaneously, their prices and timing may differ.
Online brokers match orders with the exchange’s best pricing via an online trading platform. The investor’s Demat account receives the shares after the real-time order is executed.
An offline broker takes the investor’s order over the phone or in person and executes it. The broker may execute the trade later than an online trade, and the stock price may have changed.
Thus, even if they order simultaneously, the two investors may pay different prices. For highly traded equities, price differences are likely to be minimal.
The exchange and market circumstances, not the broker, dictate a trade’s pricing and timing.