Retail investors' bullishness for Tesla is the highest in 2 years ahead of vote on EV maker's stock split

• Purchases of Tesla stock by retail investors have been "skyrocketing," Vanda Research said on Wednesday.

• The stock price has soared ahead of the EV maker's vote Thursday on a stock-split proposal.

• Tesla's stock price surged 32% in July, cutting into a year-to-date loss.

Individual investors have been piling into Tesla shares as they prepare for a potential split of the electric vehicle maker's stock, and their purchases have contributed to a recent upswing in the broader US market, according to a research firm.

"[Tesla purchases] are skyrocketing — retail investors have never been so bullish since summer '20," Vanda Research said in a weekly note published Wednesday. Net retail purchases of Tesla reached $693 million in the previous five sessions, with the maker of electric-powered sedans and SUVs topping Vanda's weekly retail-flow tracker. Apple occupied the second spot, at $379 million.

"We suspect that the strong buying activity followed the 3-for-1 stock split proposal," which goes to a shareholder vote on Thursday. Tesla, led by CEO Elon Musk, in June proposed a 3-for-1 stock split to triple the number of shares to 6 billion.

"Although a stock split shouldn't have an impact on the stock price, retail investors speculate on the fact that historically stocks rallied after the split announcement," said Vanda. "If the split will be confirmed, we could even see an acceleration of inflows – which could push the stock price higher."