No! Yoyo is actually very correct. He said when there are more sellers than buyers, meaning when there is more supply than demand. He is 100% correct.
I have seen this fallacy several times on FR, where FReepers say the market must be 'busted/manipulated/etc' because it is 'obvious' that for every seller there must be a buyer. That is not the case. Sure, when you sell 1 share of 'Spetznaz Inc' that means someone bought that 1 share. However, what if the demand for Spetznaz Inc is very low (say only 300 bids are present for Spetznaz Inc), and supply is very high (say there are 5,000 offers for the company since everyone is trying to repatriate funds to their old aunty in Florida). Because supply is so high, and demand so low, the price of the company will go down.
The inverse is also true. If there are 10,000 people who want Spetznaz Inc, and only 250 shares available of the counter, then the price will shoot up.
Anyways, the reason the price changes is simply due to demand and supply. If there are more buyers than sellers (more bids than offers), then prices go up. If there are more sellers than buyers (and offers out-hang bids), then the price will go down.
At least people on this thread are not saying the market is moving because of McCain or Obama.
I am willing to say precisely that. You talk about supply and demand, which is all very well... but you don't really talk about the why of supply or demand.
Let's look at the market performance of the last few weeks, which have been driven by the supply side. Why does a person decide to sell at fire sale prices?
The "why" part of the supply side is of course quite complicated -- but when there are "big things" afoot, I think we can look to those things for an explanation.
So for this market: people are selling because they're afraid, and want to get away from the investments that scare them (before they drop even further). Theirs is an emotional and therefore mostly irrational response. I think fears about the upcoming election may in fact explain a lot (though certainly not all) of the market volatility.
And then ... why does a seller suddenly become a buyer? Again, I think there's a huge emotional component to this -- probably less driven by McCain/Obama, than by a sudden (and irrational) hope that "things will go back to how they were."
IMO, "down" translates to a combination of election anxiety coupled with a generalized nagging fear about the markets. "Up" translates to anything that seems to assuage the nagging fear.