The S&P/ASX 200 Index (ASX: XJO) dropped 4.2% in February, with two of the big three ASX 200 mining stocks underperforming that result.

Fortescue Ltd (ASX: FMG) shares suffered the biggest setback. The Fortescue share price closed out January at $19.13 and ended February at $16.51, down 13.7%.

Early in the third trading day of March, the new month has yet to offer shareholders any reprieve. Fortescue shares are down 2.4% so far this month to $16.04. That sees the ASX 200 mining stock down 38% in a year, not including Fortescue's dividend payouts.

Falling from $117.40 a share on 31 January to $113.37 a share on 28 February, Rio Tinto Ltd (ASX: RIO) stock slid 4.4% over the month, just trailing the benchmark returns.

With shares up 3.8% so far in March to $118.13, the Rio Tinto share price is down 5% over 12 months, excluding dividend payouts.

The BHP Group Ltd (ASX: BHP) share price was the best performer of the group and the only one to beat the losses posted by the ASX 200.

BHP stock closed out January trading for $39.95 a share and ended February at $39.04 a share, down 2.3%.

Up 1.3% so far in March at $39.54, BHP shares are down 11% over 12 months, not including dividends.

What moved the ASX 200 mining stocks in February?

Iron ore is the number one revenue earner for BHP, Rio Tinto, and Fortescue. Copper comes in at number two for the ASX 200 mining stocks.

Although iron ore gained around 5% in February to close the month at US$106 per tonne, investors likely have one eye on the forecast supply boom ahead for the steel-making metal, which could sharply depress prices.

Copper also had a strong performance over the month, rising 3.5% in February to US$9,358 per tonne.

All three of the big Aussie miners also reported earnings results in February.

Here's a snapshot.

What results did BHP, Rio Tinto and Fortescue report?

BHP released its half-year results on 18 February.

The ASX 200 mining stock reported an 8% year on year decline in revenue to US$25.2 billion. With underlying attributable profit down 23% to US$5.1 billion, BHP cut its fully franked interim dividend by 28.4% to 78.5 Aussie cents per share.

Rio Tinto released its full-year results on 20 February.

While revenue was down 1% year on year to US$53.7 billion, Rio Tinto's profit after tax increased by 15% to US$11.55 billion. Management declared a fully franked final dividend of AU$3.536 a share, down 10% from last year's final dividend.

Fortescue also reported its half-year results on February 20.

Going a long way to explaining the poor performance of the Fortescue share price in February, the ASX 200 mining stock suffered a 20% year on year fall in revenue to US$7.6 billion.

With net profit after tax (NPAT) of US$1.6 billion, down 53% year on year, management cut the fully franked interim dividend by 53.7% to 50 Aussie cents per share.