poniedziałek, 10 maja 2010

Buying the Dips' a Fallacy?

Karl Denninger, a bear of bears, goes on a rant about how "buying on dips" is a bad strategy.
Basically, what it comes down to is... this guy is challenging the highly successful methods of folks like Warren Buffett.
It's a foolish endeavor but it doesn't stop occasional chestnuts from trying.
source:

One of the common "chestnuts" is that when one is in a "bull market" one should simply "buy all dips."
Really?
Let's look at a simple table, assuming you had $60,000 to invest in March of 2009. We will examine two possibilities:

1. We put the entire $60,000 in at the low, all at once.
2. We "buy the dips" in equal $10,000 increments.

Now I'm going to pick on a weekly chart and use approximate prices for each buy, because (1) you're never going to get the top or bottom tick, and (2) we're assuming you actually go to work and thus can't be watching every second of every day.
So these results look reasonably typical versus the so-called "top-ticking" and "bottom-ticking," which are usually employed by the pump monkeys.
For simplicity we will just use the S&P 500, and only from the March lows to now.
Here's the table.
Date

SPY

Dollars In

Shares

Owned

Value
3/1/2009 66.6 10000 150.15 150.15 $10,000.00
5/9/2009 87.9 10000 113.77 263.92 $23,198.20
7/6/2009 87.6 10000 114.16 378.07 $33,119.02
9/28/2010 102.6 10000 97.47 475.54 $48,790.09
10/26/2009 103.3 10000 96.81 572.34 $59,122.96
2/6/2010 103.9 10000 96.25 668.59 $69,466.37

10/1/2010 66.6 668.59 $44,528.01
Note that 10/1/2010 is a possibility, of course - a return to the lows. Let's analyze.
At today's prices, you would own 668.59 shares of SPY, which right now are worth $79,324.21. Not bad you say, in that you spent $60,000 and have an asset worth nearly $80,000, for a gain of 32%.
But the index is up 78%, which means you have underperformed by more than half ... That's not very good.
What's much worse, however, is what happens if the price collapses back to the 666 low. In that case, You lose 25% of your money.
If, instead, you simply "stuck it all in" at 666, convinced that we had a new bull market, you would have the entire retrace back down to 666 to change your mind before you lost a single penny, and right now you would be up 78% on your investment.
Before listening to the "useful idiots" on the Internet talking about "accumulation" strategies for what they claim is a "new bull market," get out EXCEL and run some of their BS cock-and-bull games through the hard truth of mathematics.
Here's reality:

The only winning strategy "for the long haul" is to be fully committed to the market when it is rising and economic fundamentals support that direction, and to be entirely out at all other times.
Such a strategy also allows you to make wrong calls on re-committing to the market at bottoms and not get materially hurt. If you instead try to "scale in" or "accumulate" and are wrong you are going to get destroyed.

You will quickly understand why I sneer at the "useful idiots'" so-called "advice" and why, if you listen to them, you're staring at an account statement that have a number at the bottom that is a lot smaller than it should be.
By the way, Jack Bogle of Vanguard sees this much the same as I do, less the advice of trying to match economics and markets. I think he's got the right general idea, but you cannot divorce your investing from an analysis of the fundamentals, or you will eventually find yourself investing in a market that is rising on crappy and deteriorating fundamentals (such as in 2006 and 2007) and see half or more of your money disappear.

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