The S&P 500 isn’t the only stock market pushing all-time highs. Consider yourself warned. - MarketWatch

1. Stock markets hit all-time highs, prompting caution among investors. 2. Historical trends indicate below-average returns after new high records. 3. DJIA shows lower average returns over long periods after hitting new highs. 4. Investor euphoria may lead to short-term gains but historically falters long-term. 5. Warren Buffett's advice suggests caution amid bullish market sentiment.