Green, green, and more green. That sums up the week on Wall Street. The most nitpicky amongst you will point out that the Dow Jones corrected slightly in the middle of the week. I'll give you that.

Yet the rally continues and the Nasdaq 100 closed the week by breaking a record. On this triple witching day, the index ended its best month of the 21st century with a gain of 17.4%. Here we are not talking about performance over a calendar month, but between two monthly expiry dates, i.e. the third Friday of each month, when several derivatives expire.

The previous record was set in April 2020 (+16.4%), in the midst of the Covid pandemic. Stocks had rebounded strongly after plunging in March, following lockdowns and the resulting shutdown of the global economy. This decline in the markets was quickly erased, thanks to massive action by central banks and governments.

Everything is looking up...

How far away that April 8 seems now. It was the day the Nasdaq 100 hit a low of just over 17,000 points, as investors braced themselves for the entry into force of reciprocal tariffs. At that point, the Trump administration was ready to turn the tables, even if it meant sending the stockmarkets into a tailspin.

In the end, it was another market that caught up with Donald Trump: the bond market. The surge in Treasuries, combined with pressure from big business leaders, finally forced the US president to back down, announcing a 90-day pause on April 9.

On that day, stock indices soared. And since then, the rebound has continued as tensions in trade relations have eased and pressure on Jerome Powell – who, remember, was threatened with dismissal in mid-April – has subsided. The past month has also been marked by the release of first-quarter corporate earnings, which have generally reassured investors.

...but for how long?

Despite all these positive factors, the scale of the rebound may seem impressive. Indeed, all losses since April 2 (the day the reciprocal tariffs were announced) have been wiped out. US indices are even back in positive territory for the year as a whole.

It is as if US trade policy had caused no damage at all. This is obviously not the case. Household and business confidence has been shaken, supply chains have been disrupted and, above all, despite a more reasonable position, tariffs are still at their highest level in a century. To date, Yale University estimates the effective tariff rate in the US at 17.8% (compared with 2.4% before Donald Trump returned to the White House). It is difficult to imagine that all this will have no impact on growth and therefore on corporate profits.

Beyond the fundamentals, the scale of the rebound may simply be the result of very pessimistic sentiment in April – as shown by the AAII (American Association of Individual Investors) survey of individual investor sentiment – and a series of more positive news stories over the past month.

The bottom line is that after coming close to a correction – a 20% decline – in mid-April, the Nasdaq 100 is now bullish again... and all this in just a month and a half. And everything still seems to hinge on the decisions of one man: Donald Trump. We will therefore conclude by quoting him at the meeting celebrating his first 100 days in office: "We've only just begun. You haven't seen anything yet."