In September 1969, the mining company Poseidon NL made a major nickel discovery at Windarra in the Shire of Laverton, Western Australia. In early September their shares had been trading at $0.80, but as information about the discovery was released, the price rose until it was trading at $12.30 on October 1. After this, very little further information came to light, but the price continued to climb due to speculation; at one point, a UK broker suggested a value of up to $382 a share.
The price of Poseidon shares quickly became too high for many investors, so some turned to other nickel stocks, stocks in other mines near Windarra, and eventually other mining stocks in general. As the price of mining shares grew, new companies were listed by promoters looking to cash in. Mining stocks peaked in January 1970, then immediately crashed. Poseidon shares peaked at an intraday high of $280 in February 1970, and fell rapidly thereafter.
By the time Poseidon actually started producing nickel, the price of nickel had fallen. Also, the nickel ore was of a lower grade than originally thought, so extraction costs were higher. Profits from the mine were not sufficient to keep Poseidon afloat, and in 1976 it delisted. Western Mining then took over the mine, operating it until 1991.