ARK Innovation ETF's stake in Tesla has climbed above $1 billion even after it has sold more than 200,000 shares in December.

Cathie Wood continues to sell Tesla Motors Inc.'s stock as it rallies, but a look at the holdings of her flagship ETF actually shows that the high-profile investor is getting more and more bullish on the electric-vehicle giant.

Wood's ARK Innovation ETF said it sold 13,040 Tesla Motors on Monday, which at the day's closing price would be valued at about $5.6 million.

So far in December, the ETF ARKK has sold 214,031 shares, valued at a little more than $92 million, as the stock has run up 24.8% month-to-date through Monday.

Meanwhile, the ETF also said that as of early-Tuesday, it owned 2,530,383 Tesla shares valued at $1.09 billion. That made Tesla's stock its largest holding by far with a 16.13% weighting.

That compares with the ETF's holding of 2,744,414 shares at the end of November, which prior to the December rally, were valued at "just" $947.3 million.

And since the presidential election, which Tesla Chief Executive Elon Musk made a big bet that Donald Trump would win, the Ark Innovation ETF has sold 432,687 Tesla shares valued at $186.3 million at current prices.

But just before the election, the 2,963,070 shares the ETF owned were valued at that time at "only" $745 million.

Investment funds will often trim stakes of their holdings as the price of their stocks rise to keep their weightings of their holdings from rising too much.

While Wood's ETF has also been rebalancing its portfolio by selling Tesla stock as it rallied, but has allowed the value of its stake in Tesla to rise sharply, suggesting Wood is getting more bullish.

Tesla's stock rose 1.2% in premarket trading Tuesday, after rising 2.3% on Monday. It was currently trading 9.2% below its Dec. 17 record closing price of $479.86.

The Ark Innovation ETF's second-largest holding is Roku Inc.'s stock with a 9.22% weighting, or well below the weighting of No. 1 Tesla.

The third-largest holding is Coinbase Global, Inc.'s stock at 8.3%.

The ETF has gained 2.2% so far in December while the S&P 500 index has slipped 1%. Over the past three months, the ETF has rallied 24.9% and the S&P 500 has tacked on 4.2%.