

DTCC's depository subsidiary, the Depository Trust Company ("DTC"), provides custody and asset servicing for more than 3.5 million securities issues from the United States and 110 other countries and territories, valued at $27.6 trillion as of year-end 2008. Asset Servicing provides a broad range of services for custody and corporate actions including safekeeping services for physical securities, data information for DTC-eligible securities, dividend, proxy and reorganization services, restricted securities services, as well as the electronic registration and transfer of securities.
Each month, the Asset Services division of DTC measures sigma levels for a variety of critical "customer-facing" transaction processes that occur throughout the life-span of eligible securities, starting with the new issuance process through DTC's Underwriting Service; continuing with the payment of income, principal and other types of periodic cash and/or stock distributions; and ending with the retirement of securities through redemption and reorganization activities.
The sigma levels evaluate the accuracy and timeliness of these processes. An "internal" sigma level measures the impact on the process of defects identified as originating within DTC. An "external" sigma level measures the impact on the process of defects identified as originating outside DTC (e.g., as the result of input by an agent or a service provider). The "overall" sigma level measures the performance of the process end-to-end, without distinguishing between the sources of the defects.
| Accuracy Defect | Timeliness Defect | |
|---|---|---|
| Internal: DTCC |
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| External: Agents & Service Providers |
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| Blended Sigma | Internal and External Accuracy Defects as a % of Total Volume | Internal and External Timeliness Defects as a % of Total Volume |