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- A more than 100-year-old buy signal just flashed in the stock market, according to LPL Research.
- Dow Theory is based on the relative price action of the Dow Jones Industrial and Transportation averages.
- The buy signal suggests there is plenty of more upside ahead for the stock market, according to LPL.
A classic stock market buy signal called the Dow Theory just flashed, according to LPL Research, suggesting that there is more upside to be had in the current rally.