In asset manager Ark Invest's flagship fund, the Ark Innovation ETF (ARKK), SpaceX and Circle are among its top 10 holdings.

On Aug. 6 local time, blockchain outlet Decrypt reported that SpaceX accounts for 4.73 percent of the portfolio and Circle 3.90 percent, making them core investments for Cathie Wood.

Based on a disclosed holdings report, SpaceX is ARKK's fifth-largest holding, valued at about $282 million. Circle is the eighth-largest holding, valued at about $233 million. The two companies joined Tesla, Coinbase, Robinhood, OpenAI, BitMine and Palantir among ARKK's top holdings.

The additions extend Ark's recent buying. Ark Invest increased its weightings even after the two companies reported second-quarter results. Recent trade disclosures show it bought 181,830 SpaceX shares across four exchange-traded funds including ARKK. It bought 273,343 Circle shares in ARKK and two other funds. Based on closing prices, the purchases were worth about $20 million and $17.3 million, respectively.

Market attention has focused on the companies' recent results and the timing of the buys. Circle said second-quarter revenue and reserve income totalled $701 million, up 7 percent from a year earlier. Adjusted EBITDA rose 8 percent to $143 million. The amount of USDC stablecoins in circulation rose 19 percent to $73.3 billion, and on-chain transaction volume jumped 151 percent to $1.48 trillion. Circle's shares moved with little volatility after the earnings release.

SpaceX shares fell 13.6 percent even as quarterly revenue rose 92 percent to $7.8 billion. Investors focused on $18.4 billion in capital expenditure, and the company's management said the money would be used to expand artificial intelligence capabilities. Despite revenue growth, the large spending plan had a bigger impact on the share price.

Ark Invest's recent portfolio rebalancing also aligns with the purchases. The firm sold part of its holdings in BitMine, Robinhood, Block and Bullish in late July. It bought about $43.5 million of Coinbase and Circle shares and added about $14.5 million to SpaceX.

Ark Invest's investment focus has become clearer. The rise of SpaceX and Circle into the top tier shows it is maintaining a strategy centred on AI, crypto, fintech and technology stocks. Circle is increasing its presence on the back of stablecoin circulation and growth in on-chain payments. SpaceX has become a holding on which Ark Invest continues to bet on long-term growth despite large capital expenditure.