Picture this. You open your laptop. You look at a chart. You see a price moving up and down. To you, that price feels like a story being told in real time — buyers and sellers, hopes and fears.
But here's the truth most people don't know. Most of those buyers and sellers aren't people at all. They're computers.
About 73 percent of all U.S. stock trades today are placed by algorithms — software programs running inside the world's biggest trading firms. That number used to be much smaller. Twenty years ago, it was closer to 15 percent. Today, the machines win.
What an algorithm actually does
An algorithm is just a set of rules a computer follows. A trading algorithm watches the market and acts on those rules without waiting for a human to push a button.
It can:
- Read price changes a thousand times faster than your eye can.
- Watch hundreds of stocks at the same time, not just one.
- Spot patterns across volume, price, and news that no human could catch in real time.
- Place a trade in less than a second — sometimes in less than a millisecond.
The big trading firms have been building these algorithms for decades. Some of the smartest people in finance work on them. The systems are the result of billions of dollars of research.
For every move you see on a chart, there's a good chance a machine moved first.
Why this changes the game for you
If most of the market is moving at machine speed, what does that mean for a person looking at a chart?
It means a few things. None of them are scary on their own. Together, they reshape how a serious self-directed trader has to think.
1. You don't have a speed advantage.
You will never out-click an algorithm. It doesn't matter how good your reflexes are. By the time you've decided to buy, the machine has already adjusted the price three times.
2. The patterns you see have already been seen.
If a chart pattern is obvious to you, it's been spotted by ten thousand machines already. The "easy" trade has already been priced in by the time it reaches your eyes.
3. But you have one big advantage they don't.
You can wait. You can sit out a bad market. You can hold a position for months. You can read a news story and think about it for an hour before doing anything. Algorithms run on rules — they have to act. You don't. That's a real edge if you use it.
So what should a self-directed trader do?
Two choices. One is to ignore the change and keep trading the way people did in 1995. That gets harder every year.
The other is to use a system that does what algorithms do well — watching everything, spotting patterns, working at machine speed — while keeping the parts that humans do better at the center of the decision. That's the model serious institutional firms have used for years. It's also the model behind Sentinel.
The point isn't to become a machine. The point is to stop showing up to a fight where the other side is already three steps ahead.
Markets are now mostly machines. You can't out-click them. But you can use a tool that runs at their speed, paired with the judgment they don't have. That's what decision-support technology is for.