Imprecate

Giant broker = small privately held company?

The biggest players in this game are not massive NYC investment banks.

Liquidity providers get paid to trade on most exchanges (maker-taker model).

ETA: That's not to say this is a good book. It's not. I'd recommend Vidyamurthy's Pairs Trading and Harris's Trading and Exchanges, but there really aren't many good books on this style of trading--anyone who knows how to do it well has no incentive to write a book on it.

I would gladly take such a position so long as the system seemed fair (e.g., seeing several long-term non-owner/management employees working there). The terms are spelled out clearly, and I'd rather work somewhere that I add value. If I can't make serious contributions in a couple months, then it's a bad deal for both me and the employer.

However, you might have trouble getting people with families to take the job, especially if they're relocating.

That's called dual trading and there are already regulations in place that prohibit the scenario you described. A broker must execute his clients' orders before his own.

In any case, most high-frequency operations are only trading for themselves.

Front-running is knowing an order is going to be inserted into an exchange's book, and sending your order before it; an example would be if a broker saw a client making a big trade and sent his order before the client's, hoping to profit when the market moved.

In most modern stock markets there is not tiered access. My order is just as good as anyone else's, and no participants are given unfair notice of another's orders. Firms can spend money and be more competitive in these markets (e.g. better analysts, faster systems, co-location), but anyone has a fair shot at competing. If an order is public, there's nothing wrong with me taking action based on it before you if my only advantage is superior technology.

If the person believed a natural counterparty would come along within milliseconds, why would he or she enter a market order rather than a passive limit order?

There are many high-frequency strategies, and front-running/manipulating markets might be one that unscrupulous firms engage in, but most would rather make legal money. The linked article doesn't make a lot of sense. For one, flash orders are no longer available on major exchanges, and secondly it's very difficult (and costly) to push most stocks 30 cents away from their fair value.

Most of the anti-HFT things I read are pushed by buy-side traders who have a hard time tricking the market into executing huge orders without moving the price, as if they ever had some natural right to do so. Trading is a competitive endeavor. If your poor execution algorithm shows your hand and someone more sophisticated notices, it's fair play for them to use that public information.

Assigning the value 0 or NULL to a pointer does not necessarily set it to address 0.

It's not that amazing. Amtrak is a quasai-governmental entity; airlines face a lot of competition. Planes fly longer distances and have no alternate way to get online. People on a 3-4h train ride might be satisfied with a Blackberry or iPhone.

Is that round-trip? I looked on Kayak and a round-trip flight tomorrow is at least $300. I don't think the busses and trains get so much more expensive at the last minute, but I could be wrong.

Not all automated trading or quantitative finance is high-frequency. A bank trading exotic derivatives OTC could use C# to generate quotes without a problem. There are at least a couple reputable prop groups I know of that use C# in real-time trading systems, but both are running more quantitative long-term strategies in options.