The Poseidon Bubble — a nickel strike that turned 80 cents into $280

In late 1969 and early 1970, shares in the small Australian exploration company Poseidon NL rose from around 80 cents to an intraday peak of roughly $280 — a gain of some 350-fold in a few months — after the firm announced a nickel discovery at Mount Windarra in Western Australia, before collapsing through 1970 in a crash that swept the whole Australian mining sector. The Poseidon bubble remains the defining speculative episode in Australian market history: a penny stock that became a national obsession and then a cautionary tale.

The trigger was real. In September 1969 Poseidon did strike nickel near Laverton, and on 1 October the company announced an early drilling result of about 40 metres averaging 3.56 percent nickel — a genuinely promising intercept at a moment when nickel was scarce and expensive. A miners’ strike against the dominant Canadian producer, Inco, and demand linked to the Vietnam War had pushed nickel to record prices, peaking around £7,000 a ton in London in November 1969. Into that backdrop a small company with a fresh strike was perfectly placed to become a sensation, and it did: the share price trebled before the assays were even confirmed, then ran on rumour and a now-notorious broker’s circular suggesting the shares might be worth $382.

What followed was a textbook mania. As Poseidon soared, dozens of other explorers floated or renamed themselves to ride the nickel theme, and ordinary Australians — many investing in shares for the first time — poured into “penny dreadful” mining stocks on the strength of names, maps, and tips. The deluge of new money chased ground that had barely been drilled, and the valuations bore no relation to any proven ore. The whole sector peaked early in 1970 and then collapsed, erasing billions and ruining countless small investors who had bought near the top.

Poseidon’s own end was prosaic. The Windarra ore proved lower-grade and costlier to extract than the frenzy had assumed; the nickel price fell back; the mine never returned a profit, and the company entered receivership in 1974 and was delisted in 1976. The bubble prompted a landmark Senate inquiry under Senator Peter Rae, which found the conduct of directors and geologists “evasive, distorted, exaggerated and simply untrue” in important respects, and helped drive the modern reform of Australian securities regulation. The case endures as the archetype of the mining-promotion bubble.