NEW YORK (TheStreet) -- U.S. large-cap stock indices remained in tight trading ranges Wednesday afternoon. The factors driving investors' skittishness were global uncertainties, marked by the approaching Sept. 18 Scottish independence referendum and the possibility of a global shift in interest rates.

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The Dow Jones Industrial Average was up 0.14% to 17,037.33. The S&P 500 was up 0.2% to 1,992.35. The Nasdaq was up 0.52% to 4,576.43. Apple (AAPL)   added on 2.85% to $100.79 a day after its new product launches. Twitter (TWTR)   popped 4.17% to $52.74 after UBS upgraded the stock to "buy."

"I think people are getting worried about Scotland saying 'yes, we want our independence' and the uncertainty that will surround that. You can almost say that it's the referendum that may have killed the bull," said Sam Stovall, U.S. equity strategist at S&P Capital IQ.

The Bank of England has hinted that it could raise rates sooner than expected amid concerns that the market has been underestimating the odds that a Federal Reserve rate hike could come sooner than later.

"Investors are beginning to worry that it's a global shift and that rates, except for Europe as a whole, might be seeing the start of their long, slow uphill climb. That's like a dark cloud hanging over investors mindsets right," Stovall remarked.

In deals news on Wednesday, Dollar General (DG) went hostile in its bid to buy rival Family Dollar Stores (FDO) . Dollar General took its offer directly to Family Dollar shareholders, launching a tender to buy Family Dollar at $80 a share. Family Dollar edged down 0.19% to $78.55. Dollar General gained 0.55% to $63.77.

Target's (TGT) new CEO Brian Cornell plans to double down on just a handful of departments like baby products and fashion, as the discounter works to bring shoppers back to its stores and better compete with online rivals, the Journal reported. Shares increased 2.09% to $62.15.

The SPDR Gold Trust (GLD) was down 0.91% to $119.75. The United States Oil Fund (USO) was off 1.18% to $34.21.

U.S. wholesale inventories rose 0.1% month-over-month in July, below the forecast of a 0.5% increase, the Census Bureau reported Wednesday.

--By Andrea Tse in New York

Follow @AndreaTTse