|
3.
Dollar-Cost Averaging
Can
Reduce the Risks of Investing in
Stocks and Bonds
If, like most people, you will be building up your
investment portfolio slowly over time with the accretion of
yearly savings, you will be taking advantage of dollar-cost
averaging. This technique is controversial, but it does help
you avoid the risk of putting all your money in the stock or
bond market at the wrong time.
Don’t be alarmed by the fancy-sounding name. Dollar-cost
averaging simply means investing the same fixed amount of
money in, for example, the shares of some index mutual fund,
at regular intervals—say, every month or quarter—over a
long period of time. Periodic investments of equal dollar
amounts in common stocks can reduce (but not avoid) the
risks of equity investment by ensuring that the entire
portfolio of stocks will not be purchased at temporarily
inflated prices.
The table
Dollar-Cost Averaging
assumes that $1,000 is
invested each year. In scenario one, the market falls
immediately after the investment program begins; then it rises
sharply and finally falls again, ending, in year five, exactly
where it began. In scenario two, the market rises continuously
and ends up 40 percent higher. While exactly $5,000 is
invested in both cases, the investor in the volatile market ends
up with $6,048—a nice return of $1,048—even though the
stock market ended exactly where it started. In the scenario
where the market rose each year and ended up 40 percent
from where it began, the investor’s final stake is only $5,915.
Warren Buffett presents a lucid rationale for this
investment principle. In one of his published essays he says:
A short quiz: If you plan to eat hamburgers throughout
your life and are not a cattle producer, should you wish
for higher or lower prices for beef? Likewise, if you are
going to buy a car from time to time but are not an auto
manufacturer, should you prefer higher or lower car
prices? These questions, of course, answer themselves.
But now for the final exam: If you expect to be a net
saver during the next five years, should you hope for a
higher or lower stock market during that period? Many
investors get this one wrong. Even though they are going
to be net buyers of stocks for many years to come, they
are elated when stock prices rise and depressed when
they fall. In effect, they rejoice because prices have risen
for the “hamburgers” they will soon be buying. This
reaction makes no sense. Only those who will be sellers
of equities in the near future should be happy at seeing
stocks rise. Prospective purchasers should much prefer
sinking prices.
Dollar-cost averaging is not a panacea that eliminates the risk
of investing in common stocks. It will not save your 401(k)
plan from a devastating fall in value during a year such as
2008, because no plan can protect you from a punishing bear
market. And you must have both the cash and the confidence
to continue making the periodic investments even when the
sky is the darkest. No matter how scary the financial news,
no matter how difficult it is to see any signs of optimism,
you must not interrupt the automatic-pilot nature of the
program. Because if you do, you will lose the benefit of
buying at least some of your shares after a sharp market
decline when they are for sale at low prices. Dollar-cost
averaging will give you this bargain: Your average price per
share will be lower than the average price at which you
bought shares. Why? Because you’ll buy more shares at low
prices and fewer at high prices.
Some investment advisers are not fans of dollar-cost
averaging, because the strategy is not optimal if the market
does go straight up. (You would have been better off putting
all $5,000 into the market at the beginning of the period.) But
it does provide a reasonable insurance policy against poor
future stock markets. And it does minimize the regret that
inevitably follows if you were unlucky enough to have put all
your money into the stock market during a peak period such
as March of 2000 or October of 2007. To further illustrate
the benefits of dollar-cost averaging, let’s move from a
hypothetical to a real example. The following table shows the
results (ignoring taxes) of a $500 initial investment made on
January 1, 1978, and thereafter $100 per month, in the shares
of the Vanguard 500 Index mutual fund. Less than $39,000
was committed to the program. The final value was over
$265,000.
Do'stlaringiz bilan baham: | 
