摘要

想象一下，当全球地缘政治紧张、政府债台高筑等增长风险日益加剧时，世界各地的股市却屡创新高，高风险投资的额外收益被压缩至多年低位。这似乎违背了金融学最基本的信条——高风险理应换取高回报。一篇新的研究论文挑战了这一传统认知，它通过对美国两个多世纪市场数据的回溯发现，股票并不总是如理论预言那样稳定地跑赢债券，甚至有过长达近百年的“暗淡期”。研究者提出，驱动市场的或许并非冰冷的“风险方差”，而是两种炽热的人性情绪：“害怕损失”与“害怕错过”。前者让投资者对下跌格外敏感，后者则驱使人们追逐那些可能带来意外暴富的资产。这一基于“恐惧”的新框架，比传统理论更能解释加密货币、迷因股等投机狂潮的兴起，它暗示我们的投资行为远比数学模型更复杂、更人性化。未来，理解并量化这两种“恐惧”，或许将成为解读市场波动与资产价格的关键。

Imagine that when global geopolitical tensions and government debt risks are intensifying, stock markets around the world are repeatedly hitting new highs, and the excess returns from high-risk investments are compressed to multi-year lows. This seems to violate the most fundamental tenet of finance—that high risk should be rewarded with high returns. A new research paper challenges this traditional view. By examining over two centuries of U.S. market data, it finds that stocks do not always consistently outperform bonds as theory predicts, and there have even been periods of 'dullness' lasting nearly a century. The researchers propose that what drives the market may not be the cold 'variance of risk' but two intense human emotions: 'fear of loss' and 'fear of missing out.' The former makes investors particularly sensitive to declines, while the latter drives people to chase assets that could bring unexpected windfalls. This new framework based on 'fear' better explains the rise of speculative frenzies such as cryptocurrencies and meme stocks than traditional theories, suggesting that our investment behavior is far more complex and human than mathematical models. In the future, understanding and quantifying these two types of 'fear' may become key to interpreting market volatility and asset prices.