1985–86: Two Markets, Two Uptrends — Decision Points Across the Gulf and the Thames

By late 1985, two equity markets on opposite ends of the globe were entering sustained uptrends that would demand very different things from traders. The Abu Dhabi Securities Exchange was navigating its own boom cycle as a frontier market in the Gulf, while the London Stock Exchange was riding the post-deregulation wave of the so-called "Big Bang" era. Neither market offered a smooth ride—the lessons they held were in the discipline required to stay the course.

The ADX Uptrend Replay (1986-01-10 to 1986-02-20) captures 58 daily bars of genuine price action beginning from December 18, 1985, a period when the Abu Dhabi market was testing its trajectory. Eleven decision points were embedded across this window, four flagged as critical—moments where traders faced binary choices about entry, exit, or position adjustment with incomplete information. The largest single-day move reached 7.3%, a figure that could shake conviction in any trend-following approach.

Thousands of miles north, the FTSE 250 Uptrend Replay (1986-01-21 to 1986-04-04) offers a contrasting laboratory. Its data window stretches from the end of 1985 through May 30, 1986, providing 104 daily bars. The mid-cap index moved from 1412.6 to 1696.5—a 20.1% run that unfolded against the backdrop of a UK economy reshaping itself through deregulation. Here the drawdowns were shallower at 5.2%, the largest single-bar move a more manageable 2.5%. The 1980s UK story was institutional expansion and market liberalization; the price action reflected that confidence.

The causal logic in both cases runs through the same mechanism: an established directional move creates a decision architecture for every participant. When prices climb, entry becomes the first puzzle—too early means carrying a drawdown before the trend validates; too late means missing the bulk of the move. The ADX window forced this choice against a larger proportional drawdown (10.3%) than the UK market presented, meaning Abu Dhabi traders who entered during the pullback faced steeper interim losses. Whether they held through that 10.3% trough determined whether they captured the 13.4% outcome or locked in a loss.

FinFable's scenario data for this window shows that across both markets, the critical decision points clustered around the same behavioral challenge: maintaining position discipline when the trend temporarily works against you. Neither the Gulf market's 7.3% single-bar volatility nor the London market's shallower but steadier progression offered certainty—only probability-weighted choices about risk and reward.

For markets, the 1985–86 uptrend episode demonstrated that sustained directional runs require not just a thesis but a structural plan for managing interim losses. For institutions, the data from these two exchanges—ADX and the London Stock Exchange—underscored that risk management during a bull phase is not about abandoning the trend but about surviving the corrections within it. The regulatory and institutional record of the 1980s, particularly in the UK with the Financial Services Act, began codifying this lesson into compliance frameworks that would evolve over subsequent decades. For traders training decisions today, these two scenarios remain useful precisely because they are not extreme events but everyday conditions: a rising market that does not go up in a straight line, and the choice every participant must make about how much interim loss they will tolerate to stay positioned.