Chief Executive Officer at Realty Income
Thank you, Andrea. Welcome everyone. Cultivating strong and enduring relationships with all our stakeholders is foundational to the success of our business. And I'd like to thank everyone listening for your continued support. Additionally, I would like to express my appreciation to all my Realty Income colleagues who continue make significant contributions towards our growth initiatives while serving our clients in all stakeholders, as one Realty Income team. We are pleased with the momentum across all areas of our business amidst an uncertain macro environment, which we believe once again demonstrates the stability of our business model and its ability to thrive irrespective of the economic cycle.
The strength of our global investment pipeline has allowed us to invest over $3.2 billion in high quality real estate in the first half of the year, including approximately $1.7 billion during the second quarter. Given this momentum we are increasing our 2022 acquisitions guidance over $6 billion. On the topic of acquisitions, I would like to mention two key developments that we are observing in the marketplace.
First, as demonstrated by the weighted average 5.7% cash cap rate we were able to achieve on our investments in the second quarter cap rates are moving higher in our target markets. Our second quarter cap rate ticked higher compared to the 5.6% and 5.4% cap rates we achieved in the previous two quarters. The positive correlation between cap rates and interest rate is also evident in our acquisition pipeline.
Second, I think corollary to rising debt and equity costs that have impacted much of our competition the pipeline of acquisition opportunities materializing for us at accretive spreads continues to grow. As a reminder, we report our cap rates on a cash basis. On a straight-line basis, we estimate our second quarter cap rate to be approximately 6.2% and generally the difference between cash and straight line cap rates ranges between 50 and 70 basis points in any given period. Transaction flow remains strong with sourcing volume totaling approximately $26 billion in this quarter, bringing year-to-date sourcing volume to approximately $60 billion. We remain selective, as we have acquired approximately 5% of sourced volume year-to-date.
During the second quarter as a percentage of revenue, approximately 39% of acquisition volume was leased to investment grade rated clients. We remain committed to our underwriting principles of partnering with well-capitalized clients who are leaders in their respective industries. Our international investment volume continues to comprise a significant percentage of our total volume representing 41% of global volume in the second quarter at a cash cap rate of approximately 5.8%.
We are encouraged that our size, scale, I'm access to well priced capital provides us with the platform and currency to actively deploy capital as we build continued momentum heading into 2023. It was an -- it was also an active quarter with regard to dispositions. We sold 70 properties generating net sale proceeds of $150 million at an unlevered IRR of approximately 9.3%. Year-to-date, we have sold 104 properties with net sales proceeds totaling $272 million generating an unlevered IRR of approximately 9.4%.
Capital recycling continues to be a value accretive activity for us, and importantly, the unlevered returns we have been able to deliver speak to the attractive risk-adjusted investment profile of our properties that have gone through our full investment cycle. Our diligent underwriting process exposure to high quality credit clients and the inherent quality of our real estate continue to deliver consistent performance. At the end of the second quarter, our occupancy was 98.9%, the highest occupancy rate we have achieved in over 10 years.
Based on our current occupancy rates and client profile we are increasing our year-end 2022 occupancy guidance to over 98%. During the second quarter we-re-leased 193 leases and achieved a rent recapture rate of 105.6%, bringing our year-to-date recapture rate to 105.9%. At quarter end 43.2% of our portfolio's annualized contractual rent was generated from investment grade-rated clients. Further our properties leased to clients on our portfolio watchlist represents less than 4% of our portfolios annualized contractual rent, which is largely consistent with the low percentages we have seen so far this year.
Finally, our same-store rental revenue increased 2% during the quarter and 3% year-to-date. With the continued strong operations performance of our portfolio, we are increasing our guidance for same-store rent growth to approximately 2% for 2022. At this time, I'll pass it over to Christie, who will further discuss results from the quarter.