It's not any different other than the speed it happens at. 20 years ago it would have taken minutes/hours for some of the drops we've seen to materialize. Now you can watch the NQ drop 100 points in less than 5 minutes, 20 years ago that would have taken hours, possibly all day. People had to wait on quote services via satellite, telephone calls to their floor traders, or actually be in the pits during the selloffs. Now it only takes us a couple seconds to connect our device of choice to our trading platforms. Market makers stop providing liquidity during these sell-offs much faster than they could 20 years ago.

> 20 years ago it would have taken minutes/hours for some of the drops we've seen to materialize.

Twenty years ago was 1998. Ten years before that, Black Monday was faster and more vicious than anything we've seen since. It remains "the largest one-day percentage decline in the DJIA" [1].

[1] https://en.wikipedia.org/wiki/Black_Monday_(1987)

Black Monday is the edge case

Not really sure what your point is. Cycles always happen for the same technical reason - more buyers than sellers lead to rising prices and more sellers than buyers lead to falling prices. Understanding what leads to these imbalances in buying and selling is the more interesting and more difficult part and the details tend to be a bit different for every cycle. Most people find these details interesting and for some people, it is their job to understand these details. The abstract idea that herd behavior is what moves markets is not that useful unless you understand exactly which herds are moving which markets and how they make their buying and selling decisions.

> Not really sure what your point is. Cycles always happen for the same technical reason

Pretty sure that was exactly my point. I'm sure someone finds the behavior "interesting", but if the same thing is happening for the same reason, I'm arguing those details that everyone finds "interesting" aren't "important".

Okay, well I think we disagree then. Most people who follow the markets know that markets are cyclical, but knowing if you're in the beginning, middle or end of the upswing or downswing portion of the cycle is what most people care about. Knowing the details are the only way you could even have a chance of correctly making these calls.

> Knowing the details are the only way you could even have a chance of correctly making these calls.

That's voodoo thinking. "OK, all those other times everyone was wrong about this. But this time we have new jargon, so we can figure it out!"

Nothing in the linked article (or anywhere else) gives you the magic you want. This is just a new way of explaining long-settled ideas.

This is like trying to debug a linked list bug via disassembly. "OK, fine, it was a bug before on x86, but look, now it's compiled for RISC-V and uses entirely different register schemes, so this time it will work!"

> more buyers than sellers lead to rising prices and more sellers than buyers lead to falling prices

That's not how any of this works. Every share bought is a share sold by some counterparty. Buyers and sellers are always in equilibrium.

The person you're replying to is telling you the truth - imbalanced delta for buyers or sellers means rising or falling prices. There is no magical equilibrium, and if there was, there would be no profit.

To explain it a step further... at this moment in time, every private and institutional investors stopped selling APPL...I can still buy a share, likely thousands of them... from the market participants that are always there: market makers. When you make a "bad call"(like selling into a rally), a market maker is likely on the other end of your trade, and they will profit from your "bad call". Now the inverse also applies, often times a market maker is taking the other end of your trade that is a good(profitable) trade for you. The market maker isn't losing though, they are just playing the odds. They are convicted that for every losing trade they take out of obligation(as a market maker), they are going to take 2 or more winning trades. They also operate with trade costs much lower than you or I(ie retail investors) have access to.

That was more reply than I originally intended to write...but you have to understand this(or fail at profitable trading). There is no equilibrium, and there are parties(market makers) ensuring that there never will be. That is their job, to create a state of constant liquidity, even if buyers and/or sellers individually are unwilling to play.

> There is no magical equilibrium

Your understanding is exactly backwards. Market makers provide the "magical equilibrium" by bridging supply and demand across time.

> and if there was, there would be no profit.

Wrong again. Even with infinite shares on the bid/ask, there's still a spread for market makers to collect.

More generally, what exactly do you think your comment proves? If a retail investor buys the sole 100 shares at top-of-book, the price (mid) moves up, but there's one buyer and one seller. Where's the "delta"? And if a big hedge fund buys 100,000 shares from 10 market makers... 100,000 shares demanded and 100,000 shares supplied. Magic!

You're arguing against an accounting identity. I know what you're trying to say: what moves prices is relative eagerness of buyers and sellers. You're just too inexperienced to be able to explain it.

The "market" is more complex than a single stream of matching buy and sell orders at specific price levels. For any given asset, there is an "order book" containing the quantities market participants are willing to buy/sell at various price levels. Lots of people coming in to buy at "the market price" eats away at the selling side of the order book, raising the market price level.

Perhaps buyers nibble at the ask. Perhaps a big order slams through. Or perhaps the posted liquidity is canceled without any trading having happened. Whatever the case, the number of shares sold is exactly equal to the number of shares bought.

Yes, perhaps I should have chose my words more carefully. When more people want to buy than sell, prices rise. When more people want to sell than buy, prices fall. The exact details of how this happens vary from market to market but in general this is how it works. For every trade there has to be a buyer and a seller. The imbalances occur in the buy and sell orders.

But to a first approximation, the numbers are the same! If anything, some of the biggest moves happen when a single (big) buyer or seller is active. It’s all about the prices participants are willing to trade at, not an imbalance of one group vs another.

I would think it depends on what scale you're looking at. It is pretty obvious that if one guy takes out a large chunk of the order book of one security, over the course of seconds, on only one side of the market, the price is going to move. If we're talking about the S&P 500 dropping over the course of a few months, I think it is accurate to say that those who want to sell are outnumbering those who want to buy.