c******n
发帖数: 5697 | 1 Is stock picking a dead art?
It has looked that way in recent weeks, as macro issues such as the solvency
of European countries and fears of a global economic slowdown have
overshadowed fundamental differences between companies. The consequence is
that stocks are moving in tandem, indicating a high degree of correlation.
Based on one-month trailing movements, S&P 500-index stocks have a
correlation of 80%, even higher than the 73% peak reached during the crisis
in late 2008, says Ana Avramovic of Credit Suisse.
The impact is felt by everyone from small investors to the most
sophisticated hedge-fund managers, who often go long and short different
stocks rather than bet on market direction. Indeed, Ms. Avramovic points out
that hedge funds tend to perform better when correlation declines and
suffer when it increases. That explains the conservative tack many funds
took in August, when some pushed their cash allocations to 90% or more.
The big fear for investors is that correlation will remain permanently
elevated. While August's turbulence can be blamed on specific macro issues,
correlation levels have trended higher in the last few years. That suggests
structural changes may have played a role.
Heard on the Tweet
Follow Heard on the Street columnist John Jannarone on Twitter at twitter.
com/jannarone and Heard on the Street at twitter.com/WSJHeard
One potential reason is the popularity of exchange-traded funds. ETFs
account for more than 30% of volume in U.S. stock markets, compared with
just 2% in 2000, Credit Suisse says. It's reasonable to expect ETF trading
to drive correlation higher because many of the vehicles are tied to stock
indexes.
Even so, ETFs were by no means the beginning of index-based trading. Mutual-
fund managers have traded baskets of stocks tracking the S&P 500 for decades
. Stock index futures began trading in 1982 and they remain far larger than
ETFs. According to CME Group, the value of CME E-mini S&P 500 futures traded
each day is more than four times the combined volume of SPDR S&P 500 ETF
and iShares S&P 500 Index ETF.
Another trend that may have boosted correlation is the decline in structured
products. Before the 2008 crisis, banks in Europe and the U.S. created and
sold many billions of dollars in structured notes tied to options on single
stocks, says Michael Schmanske, head of U.S. index volatility trading at
Barclays Capital. The vehicles generated income by selling such options for
a premium, in turn creating a larger and broader market for individual-stock
options, he says. But for reasons including counterparty risk, structured
products went out of favor in the crisis.
The result has been that a range of market participants, from big banks to
hedge funds, have adopted more macro-oriented strategies. And even if there'
s no evidence that high-frequency trading firms are a source of correlation
in their own right, they are likely to reinforce it by following other
participants and trading products like ETFs.
All that suggests that correlation could remain higher in coming years than
before the crisis. The trouble today is that there's no clear path to a
resolution of Europe's sovereign-debt crisis or a clean bill of health for
the U.S. economy. In both cases, it could take months before investors have
real visibility. In the meantime, stock pickers might want to brush up on
their macro knowledge. | Z****g
发帖数: 13731 | 2 Very interesting article, thanks for posting
solvency
crisis
【在 c******n 的大作中提到】
: Is stock picking a dead art?
: It has looked that way in recent weeks, as macro issues such as the solvency
: of European countries and fears of a global economic slowdown have
: overshadowed fundamental differences between companies. The consequence is
: that stocks are moving in tandem, indicating a high degree of correlation.
: Based on one-month trailing movements, S&P 500-index stocks have a
: correlation of 80%, even higher than the 73% peak reached during the crisis
: in late 2008, says Ana Avramovic of Credit Suisse.
: The impact is felt by everyone from small investors to the most
: sophisticated hedge-fund managers, who often go long and short different
|
|
