The average investor is making a classic mistake as the Dow marches to 30,000 By: MarketWatch January 16, 2018 at 10:12 AM EST An ‘all or none’ attitude could end up destroying their wealth, writes Nigam Arora. Read More >> Related Stocks: Bank of America Citigroup Dow Industrials SPDR Emrg Mkts Ishares MSCI ETF General Electric KeyCorp NDX PowerShares QQQ Russell 2000 Ishares ETF SPDR GOLD SPDR S&P 500 ETF Trust