The Sayona Mining share price tumbled 10% in May. Here's what pressured the ASX 200 lithium stock

The Sayona Mining Ltd (ASX: SYA) share price saw some big ups and down in May.

In fact, on 22 May, shares were up 22% for the month.

But that didn't last.

By the time the smoke cleared from the final week of trading, the S&P/ASX 200 Index (ASX: XJO) lithium stock was down 10% for the month. That compares to a 3% loss posted by the benchmark index.

Sayona Mining ended April trading for 20 cents per share. On 31 May, the stock closed at 18 cents per share.

Here's what ASX 200 investors were considering.

What happened with the Sayona Mining share price in May?

In what The Motley Fool labelled a potential 'red flag' for the Sayona Mining share price on 4 May, CEO Brett Lynch disclosed that he'd sold some 4.6 million shares on 26 April in an on-market trade.

Lynch received a bit more than $892,000 for those shares.

However, as Motley Fool analyst Sebastian Bowen noted at the time, Lynch still has a lot of skin in the game.

In fact, he acquired around 30.6 million shares on 28 April, two days after the initial selling after he exercised 30.6 million listed options.

In the lead-up to 22 May, the Sayona Mining share price largely moved higher.

Shares gained 5% on 11 May, joining a broader rally among ASX lithium stocks. That was driven by news that Allkem Ltd (ASX: AKE) and US company Livent Corp (NYSE: LTHM) were planning to merge.

Sayona also benefited from a rebounding lithium price through much of May, as the outlook for demand from China picked up pace.

Then the downturn

Unfortunately, the end of May saw those gains, and then, some evaporate.

This came after the miner emerged from a two-day trading halt on 30 May, announcing it had completed an underwritten institutional placement.

Although the company reported it had successfully raised $200 million from institutional investors, it did so at 18 cents per share. That was more than 14% below the Sayona Mining share price of 21 cents before the stock entered the trading halt.

The miner will use much of those funds to advance the development of its Moblan Lithium Project, located in Quebec, Canada.

Lynch said at the time:

This funding will speed the growth of our resource base and bring extra tonnes to the market more quickly, as we continue our advance towards becoming North America's first vertically integrated lithium producer.

The Sayona Mining share price closed down 11.9% on the day.