Chart: Global Bond Markets Outstanding in billion $ | Data Source: SIFMA 2022 Capital Markets Fact Book; Bank of International Settlements
SIFMA regularly publishes 2022 Capital Markets Fact Book sharing a broad overview of global equity and debt capital markets. Capital markets play a pivotal role in driving capital markets, the role of capital markets increases with sophistication of the economy. 
In advanced countries, the role of capital markets driving the economy is much higher compared to other economies. In the US, capital markets facilitate 75.4 percent of equity and debt financing for non-financial corporations. Equity is the most dominant mode of finance for non-finance companies in the US, Euro Area, UK and Japan except China.
For Debt Financing of non-financial companies Euro Area, UK, Japan and China use loans as a major source of capital, while for the US it’s the debt capital markets. Note Euro Area = 19 EU-member states using the Euro.
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The Global Bond Markets stood at $126.9 trillion in 2021, outpacing Global Equity Market at $124.4 trillion in 2021. The United States dominated both the equity and debt capital markets. US commands a share of 38.7 percent of the global outstanding bond markets, the market share at $49.1 trillion, market size twice that of the European Union. After EU, China has a market share of 17.2 percent of the global outstanding bond market. Japan has a massive bond market with 10.5 percent of the global bond market or ~13.3 trillion dollars. 
Global Equity Market Capitalization of listed companies at $124.4 Trillion
US, EU and China are the top three dominant countries or regions in equity and debt capital markets. In Global Equity Market Capitalization of listed companies, the United States has a lion’s share of 42 percent or $52.2 trillion dollars, 3.6 times the market share of China with a market share of 11.6 percent. EU came in third with a market share of 11.1 percent.
References
SIFMA 2022 Capital Markets Fact Book