The major currency pairs are generally regarded as the least volatile because they have historically been the most traded currencies among traders.
EUR/CHF:
The Swiss franc is a reliable currency that is regarded as a safe haven. Except for a black swan event in 2015 and a few "incidents," the CHF does not move much, particularly in comparison to other major currencies such as the Euro and the US Dollar.
USD/JPY:
Because the US dollar and the Japanese yen are both considered safe havens, price swings can be limited depending on the market environment. This can change if US interest rates rise while Japanese interest rates remain low, as the USD/JPY becomes a popular carry trade.

The least volatile currency pairs, often referred to as "major pairs," typically include EUR/USD, USD/JPY, GBP/USD, and USD/CHF. These pairs are characterized by high liquidity and stability, stemming from the economic stability and strength of the countries involved. Among these, EUR/USD is considered the least volatile due to the significant trade volume and economic integration between the Eurozone and the United States. USD/JPY is also relatively stable due to Japan's strong economy and close trade ties with the U.S. These pairs are preferred by risk-averse traders who seek predictable movements and lower risk, making them suitable for conservative trading strategies and long-term investments.