Today's rally is more about Apple, less about the Fed

Some hoped that today's slew of economic numbers would give a clear indication of what the Fed might do next week. Unfortunately, the data was mixed, though the key points — August retail sales and industrial production — both came in weaker than expected.

The chance for a September rate hike accordingly dropped — to 12 percent.

Those are pretty low odds.

Markets saw a respectable midday rally, but most of it does not have much to do with the economic data, or with Donald Trump and his economic policy speech. It has to do with Apple and a small group of other tech stocks.

Apple's huge 11 percent rally this week has contributed in a big way to any gains. Remember, the S&P 500 is market cap weighted, so the bigger stocks have an outsize influence on how the index moves. Apple, the biggest stock in the index, has the biggest effect.

Today, Apple is responsible for a more than 20-point gain on the S&P 500. This is significant, since the S&P is only up 21 points.

Apple's impact — on the S&P 500 and on the Dow — has been enormous this week as well. Apple's suppliers are also having another strong day on top of an incredible week:

Apple suppliers

(Price change, WTD)

They too are contributing to the S&P's rise, or more specifically, the S&P would be lower this week without the contribution of Apple and its suppliers.

The Dow industrials are slightly different, but the effect is the same. The Dow is a price-weighted index. Apple has the ninth-highest weighting in the index. But even here Apple has had the biggest effect this week. The Dow is 23 points higher today thanks to Apple's contribution, and roughly 92 points higher for the week, accounting for most of the Dow's 140-point gain.

Here's what some of Apple's suppliers do for the company:

  • Analog Devices: touch-screen controllers
  • Jabil Circuit: phone casings
  • Micron Tech: memory modules
  • Qualcomm : chips and electroniccomponents
  • InvenSense: gyroscopes for motiontracking devices
  • Qorvo: radio frequency components
  • Bob Pisani

    A CNBC reporter since 1990, Bob Pisani covers Wall Street from the floor of the New York Stock Exchange.