(Reuters) - U.S. stock index futures were steady on Tuesday ahead of election day voting, with traders girding up for volatile trading over the coming few sessions until a clear winner is declared.

Both Republican candidate Donald Trump and Democrat Kamala Harris predicted victory in the final day of campaigning, with polls showing the race as extremely close.

Even odds in betting markets, which many investors over the past few months have been relying on to predict the election outcome, were mixed. Harris gained a slight edge on PredictIt overnight, but Trump maintained leads on Polymarket and Betfair.

The VIX, Wall Street's "fear gauge" that indicates expected equity volatility, rose to 21.98, above its 30-day moving average of 19.65, but below the two-month high that it hit last week.

U.S. Treasury yields eased slightly from the recent highs, helping gains for rate-sensitive equities. [MKTS/GLOB]

Megacap growth stocks edged higher in premarket trading, with Nvidia up 0.7% and Alphabet adding 0.3%. Tesla jumped 2%.

Stocks viewed as bets on a win for the former president rose, with Trump Media & Technology Group up 4%, and software developer Phunware gaining 8%.

"The markets have already priced in an element of Trump winning to some degree, but we'll just have to see whatever the result is," said Ben Ritchie, head of developed market equities at abrdn.

Investors are also keeping an eye on Congressional elections to determine the balance of power in Washington. Many analysts predict a split government, which would limit the ability of the President to enact significant policy changes.

Dow E-minis were up 32 points, or 0.08%, S&P 500 E-minis were up 6.75 points and Nasdaq 100 E-minis were up 43.75 points, or 0.22%.

Meanwhile, Boeing gained 2.1% as a prolonged and crippling strike ended after factory workers accepted a new contract offer in a Monday vote.

Adding to the action-filled week ahead, the Federal Reserve will start its November meeting on Wednesday.

Markets have all but priced in a 25-basis point cut to the benchmark interest rate, but the outlook for future easing has grown more uncertain as data points to a strong economy.

The major indexes had closed lower in a choppy session on Monday.

On the data docket, September international trade numbers and October S&P Global and ISM services PMI are expected, while a handful of companies would report quarterly earnings before the bell.

(Reporting by Lisa Mattackal and Shashwat Chauhan in Bengaluru; Editing by Arun Koyyur)