I appreciate that finally someone puts forward a rational argument as to why index fonds will keep working. Books and online resources tend to not take a critical look at the system at all or they offer an answer along the lines of "Trust me!"

Having said that, only hindsight is 20/20! It feels like we are rushing into the next great financial experiment. In a complex world there is simply no telling what's actually going to happen. I assume (any sources?) that currently more money than ever is flowing into index fonds. Furthermore, chances are this is just the beginning. For instance, the buy-and-hold hype is just arriving in Europe. Blogs and online communites on this topic are currently mushrooming here! Yesterday I even saw an ad on Germany's biggest TV station right before the evening news. This is very unusual to say the least as the common people of Germany by and large have an incredible amount of distrust in anything but savings books! This current gold rush mood is just scary to me as usually, when something hits mainstream media, the magic is gone!

Anyhow, the question I am asking myself is: What will the market do now that it has access to more cash than ever? Are the markets even productive enough to put those sums of money to good use? Or is this bonanza just FU-money that encourages more reckless behavior?

I can only speculate as to what is going to happen but my hunch is that in the long term the gap between returns from index fonds and savings books is going to become a great deal smaller as more people are willing to shoulder risk for companies and thus risk premiums go down. There may still be active traders who try to find opportunities but I suspect structurally the percentage of passive investors will expand quickly and won't go back below today's percentage.

Money is cheap at the moment because growth is low, and that in turn means risk premia are lower and so on, but I don't think that's related to the rise of index funds. Then again I never understood why active management was so popular in the first place.

Yeah, the question seems to be about fresh money. You could be right that we are mostly witnessing a shift from actively managed funds to indexing. As far as my home country (Germany) is concerned indexing seems to become more attractive to people who never invested, though. Now that I think about it I am not sure whether or not this kind of money would be "fresh money" as these people stored their money in banks who were probably investing it.

> Money is cheap at the moment because growth is low, and that in turn means resk premia are lower and so on, but I don't think that's related to the rise of index funds. Then again I never understood why active management was so popular in the first place.

As I understand it, risk premia is not related to growth. It is simply the costs to transfer risk to someone else. Active management was probably high in the past as banks had little incentive to sell passive investment plans: If people don't constantly buy and sell they don't cause transaction costs and thus income for the bank. Active and passive management are both neither inherently wrong or right. Until now active investment has been irrational but it could theoretically change if the share of money passively invested is high enough, say (made up number incoming) 80%.

My point was that investors targeting a particular rate of return are having to take on more risk (because growth is low), which in turn lowers the risk premium through ordinary supply and demand.

Maybe. Money is cheap if you are a bank or a government backed borrower (like a conforming mortgage loan in the US).

If you have collateral, like the car you're borrowing against, money is kind of cheap ... also if you have a perfect credit history.

But I am not so sure that money is cheap right now out in the real world. If you are a new business with no track record or a consumer with poor credit history I think money might be quite expensive for you ...

Really? My understanding was that (non-mortgage) subprime lending was higher than ever, business loans were cheaper than ever...

Doesn't that suggest people on average have had a misplaced fear of stock (indices) in the past, and that capital is now more efficiently allocated? Sounds like it would make the world better off.

Yes, I think this bit is pretty much agreed upon today. Hence the run for indices.

> and that capital is now more efficiently allocated?

That sounds likely to me.

> Sounds like it would make the world better off.

As tempting as it is to argue one way or another ... I think that's an impossible statement to make.

But like I initially said, it's all just speculation anyhow. Tbh these kind of discussions are inherently whacky. Chances are everything you've quoted from me is flawed on so many levels if one takes a closer look. Discussing finance is mostly a fool's errand.

I'm having trouble understanding why this is the case. Care to clarify?

That being said, consider what would happen if stock prices did start to vary randomly - if you had actual research suggesting the price was too high or too low, you could trade accordingly. This would net you a profit, and also help push the price in the opposite direction, towards whatever a reasonable price is.

The larger the deviation from the "correct" price, the larger the potential profits are to be had. So if the problem ever starts to be significant (i.e. a few cents of deviation caused by index funds), this means a very large potential profit for any active funds or traders out there. And so we would expect the system to reach an equilibrium - where there are just enough active funds and traders to snatch up the profits that arise from tiny price errors and distortions caused by index funds. In effect, the index funds are paying those remaining active funds and traders a tiny "management fee" (in the form of exploitable trading behavior) to figure out the appropriate price of stocks for them!

Imagine that 99.98% of all investors are index funds, and there is a company BigCo that is at some point is at the top of the market. So pretty much every index fund invests in it.

Then suppose BigCo makes some move that would traditionally be a mistake. Like it has some scandal, the sales drop off, etc. Say it even has a bad quarter.

How do I, an active investor (among the remaining 0.02%), make profit from the arbitrage? For the stock price of the company to fall, there'd have to be no buyers at the given price. But the index funds will keep investing in it. Why would it drop off even a little?

This would require a long-term view similar to how Berkshire Hathaway is acquiring businesses. If active investors' short-term price speculation were reduced in favor of long-term bets, that might be a good thing for businesses and the economy overall.

And of course, if this situation actually becomes commonplace, chances are the market for index funds is going to self-correct since a well-performing stock needs either solid dividends or above-average growth. A market with 100% indexing can not give you above-average growth, and dividends depend on actual business performance.

Good stock pickers > Index Funds (blind money) > Bad stock pickers

By investing on index funds you are betting in the average of the average (a fund is already an average of undervaluated and overvaluated stocks).

However, by investing on managed funds your probability of having profits over index funds is low: even if stock pickers that beat the market (by definition) amount to 50%, extra fees make most of them still less profitable to investors than passive funds.

[edited]

You can only tell them after the fact

[edited]

http://longbets.org/362/

The implication of the random walk theory is that current information is already uilt into the price of the stock. That is only true insofar as there are active traders acting on that information. The parent is merely explaining why those traders will exist, and why you only need a small part of the market to actively trade.