Wall Street futures were mixed on the downside pre-bell Tuesday as traders digested big bank earnings and weighed media reports that China-based semiconductor-maker CXMT will introduce new, competitive memory chips later this year.

In futures, the S&P 500 was off 0.1%, the Nasdaq declined 0.5%, and the Dow Jones was up 0.2%.

West Texas Intermediate crude oil traded down 2% to $91.87, and yields on 10-year US Treasuries eased mildly to 5.18%, in morning action.

The VanEck Semiconductor fund (SMH) traded down 1.6% pre-bell, after a 2% decline on Monday.

On the earnings front, Wells Fargo (WFC) traded down 0.4% pre-bell after the bank reported Q3 earnings above outlooks, but missed on revenue and met guidance expectations.

JPMorgan Chase (JPM) traded down fractionally pre-bell after the bank reported Q3 earnings and revenue below expectations in morning hours.

Johnson & Johnson (JNJ) lost 3.3% pre-bell after the healthcare enterprise reported fiscal Q3 earnings and revenue above expectations, but issued earnings guidance below expectations.

Asian exchanges traded unevenly overnight, with a 5.5% divot on Seoul's KOSPI index, home of chipmaking giants SK Hynix and Samsung Electronics.

European bourses tracked moderately north at midday on the continent.

On the economic calendar, the NFIB Small Business Optimism Index declined to 97.9 in September from 98.7 in August.

The existing home sales bulletin for September posts at 10 am ET.

Federal Reserve Governor Christopher Waller, Richmond President Thomas Barkin, and Boston President Susan Collins are slated to speak on Tuesday.

In pre-market action, Bitcoin traded at $83,357, and spot gold commanded $4,183 an ounce.