Canadian investors felt the chip rout at one remove on Friday. The S&P/TSX Composite edged up 0.1% to 36,177 and added 0.8% on the week, with oil producers offsetting a technology selloff in which Shopify fell 5.1%, Celestica 3.9% and Constellation Software 3.0%, according to Trading Economics. The Philadelphia Semiconductor Index, meanwhile, closed at 11,137.3 after its eighth straight loss, the longest run since October 2008.
A portfolio that looks calm on a TSX screen can still carry the damage elsewhere, in the US equity funds and Nasdaq exposure that the home index does not show. The Nasdaq-100 lost 5.49% over the week, its worst weekly decline since the week that began March 31, 2025. The size of that loss is not the behavioural story. The story is what the number of consecutive losses does to judgment.
The Headline Is Doing the Anchoring
Every outlet led with the same fact: the longest losing streak since 2008. Tversky and Kahneman showed in 1973 that people judge how likely something is by how easily examples come to mind, and the 2008 financial crisis is the most vivid example available. The comparison arrives with a story attached, one of systemic failure, forced selling and years of recovery.
The underlying record does not carry that story. TECHi counted daily closes back to 1994 and found 16 runs of seven sessions or more, eight of which reached eight sessions. The October 2008 run cost the index 19.8% and unfolded during a banking crisis. This one cost 15.7%, ranking fourth among the 16, and it unfolded while ASML reported record quarterly sales of 11.7 billion euros and TSMC reported third-quarter revenue up 50.9% from a year earlier.
The index fell on both days anyway, by 4.30% on Oct 14 and 0.88% on Oct 15. Strong evidence and a falling price can coexist, and the streak headline invites investors to resolve the contradiction in favour of the price.
The Philadelphia Semiconductor Index lost 15.7% across eight consecutive closes, a slide that began on Oct 6 and deepened on the two days the largest companies in the industry reported record results.
The bear market line is drawn at 80% of the June 22 record close. ASML reported on Oct 14 and TSMC on Oct 15, and the index closed lower on both days.
Loss Aversion Arrives in Daily Doses
Kahneman and Tversky, publishing in 1979, showed that losses weigh more heavily than equal gains, and their 1992 estimates put the multiple near 2.25. Benartzi and Thaler extended the idea in 1995 as myopic loss aversion: investors who evaluate holdings often experience more frequent losses and demand more compensation for holding risk. A 15.7% decline delivered as eight consecutive red closes is close to the maximum dose of that effect.
The index now sits 23.9% under its June 22 record close of 14,634.72, past the 20% line many investors use to define a bear market. Yet the Cboe Volatility Index closed Friday at 19.99, up from 15.01 on Oct 6. That is a reading of concern, not of panic, and it shows how concentrated the damage is.
All 23 chip and AI hardware stocks TECHi tracked fell between Oct 6 and Oct 16, and 18 of them lost at least 10%. Analog and power chips fell an average of 10.4%, while the AI cloud operators CoreWeave and Nebius fell about a third. Over the same window the Energy Select Sector fund rose 7.0% and the Consumer Staples Select Sector fund rose 7.1%. A client holding a thematic chip fund and a client holding a balanced portfolio lived through different weeks.
What History Says About the Rebound Instinct
A run this long invites two opposite predictions, that the selling is exhausted and that the break has only started. Both are forms of extrapolation, and the base rate supports neither. After 15 earlier runs of seven sessions or more, the median 20-session change was negative 0.2%, and seven of the 15 were higher after 20 sessions.
Among the earlier runs of eight sessions or more, two were higher by more than 15% twenty sessions later and five were lower. The May 2002 run kept falling another 20%. TECHi concludes that streak length has not worked as a timing signal, and it cautions that the sample is small and price-only.
TECHi also reads the shape of the selloff as fitting a financing scare best, since companies that must keep borrowing to build capacity fell furthest, and it labels that a reading of the ranking, not a finding. The distinction matters behaviourally. A confident single-cause story is the most comfortable thing for a frightened investor to adopt.
Where the Cost Shows Up
The financial damage of a streak is the market move. The behavioural damage is the decision made inside it. Selling after the eighth loss locks in a decline that history says is no more likely to reverse than to extend, and buying because a bounce feels overdue is the mirror error.
Two scheduled events will test the narrative. Lam Research reports its September quarter on Wednesday, Oct 21, and the Federal Reserve meets on Oct 27 and 28, its first meeting since the 3.7% US inflation reading. Investors who set a review schedule and rebalancing bands before the streak began have removed the decision from the moment when the bias is strongest.