Exercise 2: Why +400% Then -78% Doesn't Mean "Back to the Start" — Possible Solution ==================================================================== Using this chapter's own real figures, treating the pre-1995 NASDAQ level as a starting value of 1 (a simple multiplier, to make the percentages easy to track): A rise of 400% means the index grew to 5 times its original value: 1 + 400% = 1 x 5.00 = 5.00 (the real March 2000 peak) A fall of 78% FROM THAT PEAK means the index lost 78% of its peak value, retaining only 22% of it: 5.00 x (1 - 0.78) = 5.00 x 0.22 = 1.10 So after both real moves, the index ended up at approximately 1.10 times its original 1995 starting value - still about 10% ABOVE where it started, not back to square one. WHY THIS ISN'T THE SAME AS "BACK TO THE START" The key mistake to avoid is treating the two percentages as if they cancel out symmetrically - they don't, because each percentage is calculated against a different base value. The 400% rise was measured against the smaller, original 1995 starting value. The 78% fall, however, was measured against the much larger 2000 peak value (5.00 in this simplified example) - a genuinely different, much bigger number. Losing 78% of a much larger figure still leaves more real value behind than the original starting point, even though 78% sounds like it should nearly wipe out a 400% gain. WHY THIS MATTERS FOR UNDERSTANDING REAL MARKET MOVES This is a real, general mathematical pattern worth remembering whenever comparing a percentage rise against a later percentage fall: they are never simply symmetric or self-canceling unless the percentages happen to be calculated against exactly the same base value, which a rise followed by a fall almost never is. In this specific real case, the dot-com bubble's own trough still left the NASDAQ meaningfully above its own pre-bubble starting level - a real, concrete illustration of why "it fell X% after rising Y%" needs actual calculation, not just intuition, to know where an index or investment genuinely ended up. ANSWER: Starting from a value of 1, the NASDAQ's real 400% rise took it to 5.00 (its March 2000 peak), and the subsequent real 78% fall from that peak brought it down to approximately 1.10 - still about 10% above its original 1995 starting level, not back to where it began. This is because the 78% fall was calculated against the much larger peak value, not the original smaller starting value, so the two percentages don't cancel each other out symmetrically - a real, general reason a large percentage rise followed by a large percentage fall rarely returns an investment exactly to its own starting point. WHY THIS WORKS AS AN ANSWER ------------------------------ This correctly performs the real, sequential percentage calculation using the chapter's own stated figures, and explains the underlying mathematical reason (different base values) that a rise and a subsequent fall of different percentages don't simply cancel out.