The Nasdaq-100 PowerShares QQQ (NasdaqGM: QQQ) was firmly in the red Wednesday despite the Dow rallying more than 100 points. The divergence in these major stock benchmarks illustrates the sway that market giant Apple (NasdaqGS: AAPL) holds over tech indices.

Apple shares were down more than 4% following news that some clearing firms are raising margin requirements for the stock. Shares of the iPhone maker are down more than 20% from the September high, pushing the stock into bear market territory.

On the chart, Apple shares are nearing a so-called death cross, a technical pattern in which the 50-day moving average crosses below the 200-day.

“It’s one of the best names out there, but those people who think it’s going to have a rocket ship ride to $1,000 may be mistaken because competition is coming in and with a market cap this large, the expectation is quite high for the name,” said Colin Gillis, senior technology analyst at BGC Financial, in a CNBC report.

QQQ, the Nasdaq-100 ETF, was off nearly 1% in afternoon trading Wednesday. Apple is the largest stock in the portfolio at 18% of the fund.

Next week, Facebook (NasdaqGS: FB) will join the tech-heavy ETF’s tracking index. The social network will be added to the Nasdaq-100 at the start of trading next Wednesday, WSJ.com reports.

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