100 days: The US stock market's rollercoaster ride since Trump took office

00 Days: The Ups and Downs of the US Stock Market Since Trump Became President In the world of finance, few metrics capture the public’s attention like the stock market. The economy, investor sentiment, and national confidence are seen as pulse checks. When Donald J. Trump took the oath of office on January 20, 2017, Wall Street was already in motion. His unexpected victory had sparked a post-election rally, commonly dubbed the “Trump Bump,” fueled by promises of tax cuts, deregulation, and an aggressive pro-business agenda. But what followed over the next 100 days—and indeed throughout his term—was a wild, often unpredictable rollercoaster ride for U.S. financial markets.

The Initial Surge: Trump Bump in Full Effect

The stock market surged immediately following Trump's inauguration. Investors were optimistic that corporate taxes would be slashed, infrastructure spending would soar, and regulations, particularly in finance and energy, would be rolled back. Within Trump’s first 100 days, the Dow Jones Industrial Average climbed roughly 6%, while the S&P 500 gained over 5%.

This rally was based less on economic fundamentals and more on investor belief in the potential of Trump’s policies. It marked one of the strongest post-inauguration stock performances for a president in modern U.S. history. Key sectors such as financials, industrials, and energy saw significant gains, pricing in an imminent pro-growth economic wave.

Policy Meets Reality

However, markets are not powered by promises alone. As the weeks passed, the limitations of governing became apparent. Trump's pledge to repeal and replace the Affordable Care Act (Obamacare) encountered legislative gridlock. This early policy failure in Congress caused markets to cool slightly, sparking questions about whether Trump’s more ambitious goals—like tax reform and infrastructure—would suffer the same fate.

The first 100 days became a tug-of-war between bullish optimism and political realism. By late April 2017, the administration had not yet passed any major legislation. Nonetheless, strong corporate earnings and a robust labor market supported the stock market. Tax Cuts and the 2017 Rally

The market’s patience was rewarded in December 2017 with the passage of the Tax Cuts and Jobs Act, a sweeping overhaul of the tax code that slashed the corporate tax rate from 35% to 21%. This legislative win ignited another major rally, with the Dow crossing 25,000 in early January 2018.

Investors cheered the windfall this would bring to corporate bottom lines. Companies responded by announcing share buybacks and dividend increases, adding fuel to the rally. The Nasdaq, heavily weighted with tech giants, soared as well, with companies like Apple, Amazon, and Google leading the charge.

Volatility Returns: Tariffs, Tweets, and Trade Wars

As markets settled into 2018, the ride turned bumpier. President Trump’s aggressive trade policies, particularly targeting China, began to roil markets. Announcements of tariffs, retaliatory measures, and sharp rhetoric sparked frequent sell-offs. For the first time in years, volatility returned in force.

Investors attempted to price in the economic impact of escalating trade tensions as Wall Street's fear index, the VIX, spiked multiple times. Semiconductor and manufacturing stocks, heavily exposed to Chinese markets, were especially hit. Trump’s unpredictable use of Twitter to make policy pronouncements added a layer of uncertainty not seen in previous administrations.

COVID-19: The Black Swan Event

While trade tensions defined much of Trump’s economic narrative, nothing compared to the market upheaval triggered by the COVID-19 pandemic in early 2020. As the virus spread globally, markets crashed. In March 2020 alone, the S&P 500 lost 30% of its value in record time.

Circuit breakers—mechanisms to halt trading after rapid drops—were triggered multiple times. Investors were in panic mode, unsure of the virus's impact on global supply chains, consumer spending, and corporate solvency.

However, in an extraordinary response, the Federal Reserve slashed interest rates to near zero, injected liquidity into the markets, and launched unprecedented lending facilities. Simultaneously, Congress passed massive stimulus packages, including direct payments to Americans and support for businesses. These coordinated efforts helped stabilize markets, and by mid-2020, stocks had rebounded sharply.

Tech Stocks and the K-Shaped Recovery

The pandemic didn’t treat all sectors equally. While travel, retail, and energy lagged, tech stocks boomed. Companies that enabled remote work, digital payments, streaming, and e-commerce saw explosive growth. Zoom, Amazon, and Netflix became household names—and investor darlings.

This divide gave rise to the “K-shaped recovery,” in which certain sectors and socioeconomic groups recovered rapidly while others struggled. The stock market, increasingly driven by a few mega-cap tech firms, soared even as unemployment remained high and small businesses shuttered.

The Final Stretch and Election Jitters

As the 2020 election neared, market anxiety rose. Trump’s handling of the pandemic, civil unrest, and disputes over mail-in voting added to the uncertainty. Yet, Wall Street’s overall trend remained upward, reflecting a belief that stimulus and Fed support would continue regardless of the election outcome.

Markets surged in late 2020, partially fueled by the announcement of effective COVID-19 vaccines and the transition to a new administration, following a brief dip following the election. The Dow ended the Trump presidency above 31,000, a significant gain from the roughly 19,800 level on his inauguration day.

Assessing Trump’s Market Legacy

Looking back, the Trump-era stock market is difficult to evaluate through a purely partisan lens. His administration led one of the longest bull markets in U.S. history, on the one hand. Investment and earnings increased as a result of deregulation, business-friendly rhetoric, and corporate tax cuts. On the other hand, volatility spiked during his tenure, driven largely by self-inflicted trade tensions and unconventional communication strategies. Moreover, the market's performance was increasingly decoupled from broader economic health, raising questions about inequality and financial market overreliance on Fed intervention.

Conclusion: The Market Is Not the Economy

The first 100 days of Trump’s presidency set the tone for four years of market drama: bold rallies, steep drops, and massive rebounds. Investors learned to read between the lines of tweets, brace for tariff announcements, and interpret policy as much from tone as from substance.

Trump’s presidency underscored a long-standing truth in American finance: the market is not the economy. Wall Street soared while millions struggled with job losses and pandemic disruptions. For better or worse, the Trump era reminded us that stock prices often reflect hope, speculation, and liquidity more than economic fundamentals.

Whether remembered as an era of prosperity or peril, one thing is clear: the stock market during Trump’s time in office was anything but boring.