Richard M. McVey
Chairman and Chief Executive Officer at MarketAxess
Good morning, and thank you for joining us to review our first quarter results. In the first quarter, we continued to execute our long-term growth strategy, and total revenue of $186 million was our second highest quarter ever. EBITDA for the quarter was $106 million, and EBITDA margin was 57%. Trading volumes rebounded strongly as market conditions improved from prior quarters.
Total average daily trading volume reached a record $38 billion, we achieved the second highest level of average daily volume in total credit, and we delivered record U.S. Treasury emerging markets and municipal bond average daily volume. Total active clients trading on the platform also reached a new all-time record for the quarter. These strong business results are a clear sign that the investments we are making to expand our foundation for growth are paying off.
Importantly, as spreads have widened, the benefits of our unique all-to-all liquidity came through with total Open Trading estimated transaction cost savings rebounding to over $200 million for the quarter. Average transaction cost savings per trade through Open Trading were up approximately 60% from recent quarters. In our unique Live Markets all-to-all order book, we are continuing to gain traction across both rates and credit with a new quarterly record ADV in U.S. Treasuries of $25 billion, up 38% year-over-year and record volumes and active clients in corporate bond Live Markets.
Beyond our core business and protocols, we are making excellent strides in new product areas. We registered a record $14 billion in portfolio trading volume. Emerging market -- local market trading reached a new record of 22%, municipal bond trading ADV was a record $288 million, which benefited from the integration of MuniBrokers. And we launched our MarketAxess 400 Index to create a highly tradable corporate bond index, as well as Axess All Prints, a real-time European fixed income trade tape. We believe our growing global product footprint, record numbers of institutional clients and improving market conditions create a strong foundation for long-term growth.
Slide 4 provides an update on market conditions. Credit spread and interest rate volatility have both increased over recent months, driving record trading activity on the platform. The first quarter saw high levels of investment-grade corporate bond issuance, which is likely to slow for the balance of the year. While we are only three weeks into the new quarter, estimated high-grade, high-yield and emerging market share are all tracking well above Q1 levels. Combined U.S. high-grade and high-yield estimated market share is currently above 20%, up from 19.1% in Q1. When combined with share trends in Eurobonds, munis and U.S. Treasuries, the breadth of our market share gains has never been better.
Central Bank monetary policy has shifted dramatically with higher rates and the likely reduction of balance sheets to reduce inflationary pressures. We believe that higher bond yields and less Central Bank quantitative easing will support higher market volatility in the periods ahead. Higher bond market volatility is already driving increased demand for Open Trading liquidity in U.S. Treasuries and credit versus prior quarters. This is coming through in market share trends, active client firms and overall trading volumes.
Slide 5 illustrates our expanding global client network. The increasing network effect on our platform is clearly illustrated by the addition of new clients globally. During the first quarter, we set new records with 1,913 active client firms globally with over 1,000 firms integrated from their order management systems. Our increased investment internationally is paying off with a new record 975 firms trading actively outside of the U.S. with notable traction in Asia.
For the first quarter, a record 32% of our global credit trading volume came from clients outside the U.S. Additionally, the number of active institutional investor and dealer traders set a new record at approximately 11,200 traders. 92% of our trading volume continues to be with institutional investor clients and the remaining 8% represents dealer-to-dealer trading volume. In Europe, we now have nearly 1,000 client firms utilizing our post-trade regulatory reporting services, up from 440 firms at the end of 2020.
Slide 6 illustrates the tremendous growth opportunity that is driving our approach to investing. We have included this slide again this quarter because it reflects the enormous opportunity we have in front of us and the expanded foundation we have established to diversify our business. Our broader product footprint and growing menu of protocols create multiple options for growth. We are in very early stages of electronification in most of these markets, and we estimate they conservatively represent a $9 billion revenue opportunity for our sector. We believe it is also likely that all-to-all trading and trading automation will lead to higher levels of overall bond trading velocity. We are excited about the many ways we are pursuing a larger data opportunity. The launch of our MarketAxess 400 Index and our real-time European fixed income trade tape are both examples of this investment. Finally, we continue to expand our post-trade business with additional clients and post-trade services.
Now let me turn the call over to Chris to provide more detail on the significant progress we are making with our investments in new initiatives.