It is difficult to bid before the opening, unless you are a big fund, or your price is weaker than the transaction price of both parties, you can knock in after the opening.
Arbitrage: In finance, it is defined as the act of buying or selling the same or basically the same securities at favorable prices in two different markets. The financial instruments in the portfolio can be the same or different. In market practice, the word "arbitrage" has a different meaning from the definition. In practice, arbitrage means high-risk positions, which may bring losses, but are more likely to bring benefits.