For the uninitiated, "spoofing" does NOT mean what you think it might, e.g. spoofing network packets or making fake trade records. "Spoofing" simply means placing orders on the exchange orderbook which one supposedly does not intend to execute. I've never understood this, because any bid/ask order on the orderbook CAN be executed against, until it is canceled. If they were "flashing" large bids/asks that were being i…
Ideally the less manipulation you have the better working market. So, it's good that spoofing is illegal. Their only purpose here was to: "Through these spoof orders, the traders intentionally sent false signals of supply or demand designed to deceive market participants into executing against other orders they wanted filled. " That being said, algos could have hit the large spoof bid, but imagine if it was legitimat…
I think this is debatable. There's an ideal where no one spoofs and market prices are accurate at all times. But it's very difficult to enforce perfectly - there is no bright line test for whether you wanted a trade to execute or not, when you placed it. So in practice you are just always partially enforcing it and keeping the manipulation not too obvious.
The other possible solution is that anyone can place any order of any type any time they like, for any reason. The constraint is that if you place an order and it trades, you have to honour it. This leads to a situation where no one can trust the order book, but traded prices do reflect market truth - because of course no one wants to trade at an inaccurate price (not in their favour). The plus side is that it's much easier to make the system work. You don't have to run an arms race with people using sophisticated manipulation which can't yet be detected or prevented.
It's not clear whether order books giving (somewhat) accurate information is worth both the direct costs of enforcement and the potential unfairness of some spoofing rules being enforced and some not. It might be - but it's not clear that it definitely is.