The primary drivers of a bull market are usually a combination of economic, political, and financial factors. One of the most important drivers of a bull market is a strong economy with growing corporate profits, low unemployment rates, and low inflation. This typically creates a positive business environment and stimulates consumer spending, which can boost stock prices.

Another important driver of a bull market is low-interest rates. When interest rates are low, borrowing costs are lower, making it easier for companies to finance investments and expansions. This can lead to increased earnings and stock price appreciation.

Investor sentiment and confidence also play a significant role in driving a bull market. When investors are optimistic about the future, they tend to buy stocks, which can push up prices. Positive news about individual companies or industries can also contribute to investor confidence and drive a bull market.

Finally, government policies and central bank actions can also have a significant impact on the direction of the stock market. For example, fiscal stimulus measures such as tax cuts or infrastructure spending can boost economic growth and support a bull market. Similarly, monetary policies such as quantitative easing or interest rate cuts can provide liquidity to the financial system and stimulate investor demand for stocks.

In a bull market, where asset prices are rising and investor confidence is high, several primary drivers contribute to its momentum:

1. Economic Growth: Strong economic fundamentals, including rising GDP, low unemployment rates, and increasing consumer spending, fuel optimism among investors, driving demand for assets.

2. Corporate Earnings: Positive corporate earnings reports and robust financial performance from companies encourage investment, as shareholders anticipate higher returns and dividends.

3. Low Interest Rates: Central bank policies that maintain low interest rates stimulate borrowing and investment, making it cheaper for businesses to expand and individuals to access credit, boosting asset prices.

4. Investor Sentiment: Positive investor sentiment and a "fear of missing out" (FOMO) mentality can create a self-perpetuating cycle of buying, as investors rush to capitalize on perceived opportunities, further driving up prices.

5. Technological Innovation: Breakthroughs in technology and innovation can drive productivity gains, enhance efficiency, and create new investment opportunities, contributing to overall market optimism and growth.

These factors, among others, work in tandem to sustain a bull market's upward trajectory.