| OAP3 | Octopus Apollo Vct PLC | 47.80 | 44.00 | 47.80 | 661 | 1.50 | | 3.24 | |
| OAUE | UBS Etf | 42.76 | 42.76 | 42.76 | 11 | 0.00 | | 0.00 | |
| OBD | Oxford Biodynamics PLC | 0.3100 | 0.2670 | 0.2800 | 67.3M | 0.0250 | | 9.80 | |
| OBI | Ondine Biomedical Inc. | 8.000 | 7.500 | 8.000 | 10.0K | 0.000 | | 0.00 | |
| OCDO | Ocado Group PLC | 293.1 | 280.0 | 282.0 | 1.1M | -3.7 | | 1.30 | |
| OCI | Oakley Capital Investments Limited | 567.5 | 560.0 | 562.0 | 125.9K | 2.0 | | 0.36 | |
| OCN | Ocean Wilsons (Holdings) LD | 1,200 | 1,175 | 1,180 | 33.8K | 0 | | 0.00 | |
| OCTF | First Trust Global Funds Public Limited | 2,050 | 2,050 | 2,065 | 150 | 26 | | 1.24 | |
| OE08 | Bank Of Montreal | 100.4 | 100.4 | 100.4 | 1.0M | 0.0 | | 0.00 | |
| OE61 | The Kingdom Of Morocco | 108.0 | 108.0 | 108.0 | 200.0K | 0.0 | | 0.00 | |
| OFG | Octopus Future Generations Vct PLC | 79.50 | 79.50 | 79.50 | 0 | 0.00 | | 0.00 | |
| OGDC | Oil And Gas Development Company Limited | 8.000 | 8.000 | 8.000 | 6.0K | 0.000 | | 0.00 | |
| OGG9 | Gold Bullion Securities LD | 362.0 | 362.0 | 362.0 | 0 | 0.0 | | 0.00 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 127.8 | 125.8 | 127.3 | 1.1K | -0.5 | | 0.36 | |
| OGN | Origin Enterprises PLC | 4.247 | 4.247 | 4.200 | 353 | 0.000 | | 0.00 | |
| OGOL | Global X Metal Securities | 56.35 | 56.35 | 56.35 | 15 | -6.93 | | 10.95 | |
| OGZU | Wisdomtree Metal Securities Limited | 379.8 | 374.8 | 378.3 | 192 | -2.0 | | 0.53 | |
| OHGR | One Health Group PLC | 253.0 | 251.7 | 253.0 | 18.0K | 2.0 | | 0.80 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 105.3 | 105.3 | 105.3 | 11.0M | 0.0 | | 0.00 | |
| OIG | Oryx International Growth Fund LTD | 1,285 | 1,211 | 1,285 | 6.2K | 53 | | 4.26 | |
| OIGB | Vaneck Ucits Etfs PLC | 19.84 | 19.53 | 19.58 | 14.7K | -0.10 | | 0.50 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 26.58 | 26.14 | 26.28 | 4.1K | -0.06 | | 0.24 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 679.0 | 678.8 | 678.8 | 105.6K | 16.6 | | 2.51 | |
| OIL3 | UBS AG | 82.86 | 82.86 | 84.72 | 1 | -2.96 | | 3.52 | |
| OILG | UBS AG | 7,466 | 7,466 | 7,634 | 0 | 76 | | 1.00 | |
| OILU | UBS AG | 124.0 | 124.0 | 125.0 | 1 | -3.7 | | 3.01 | |
| OIP9 | Shell International Finance B.V | 97.70 | 97.70 | 97.70 | 0 | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 175.0 | 169.7 | 174.0 | 281.3K | 2.8 | | 1.61 | |
| OM9S | Yorkshire Water Finance PLC | 69.60 | 69.60 | 69.60 | 100.0K | 0.00 | | 0.00 | |
| OMG | Oxford Metrics PLC | 55.40 | 54.40 | 54.40 | 580.8K | 0.40 | | 0.74 | |
| OMI | Orosur Mining INC | 30.30 | 28.50 | 29.25 | 7.66M | 2.25 | | 8.33 | |
| OMIP | One Media Ip Group PLC | 3.980 | 3.750 | 3.980 | 125 | 0.230 | | 6.13 | |
| OMU | Old Mutual Limited | 67.77 | 66.60 | 67.60 | 247.2K | -0.40 | | 0.59 | |
| OMXS | Ishares Iv PLC | 818.5 | 812.9 | 818.0 | 3.9K | 3.5 | | 0.43 | |
| ONDO | Ondo Insurtech PLC | 19.50 | 17.00 | 19.50 | 1.13M | 1.70 | | 9.55 | |
| ONT | Oxford Nanopore Technologies PLC | 157.2 | 151.2 | 154.0 | 637.8K | -2.0 | | 1.28 | |
| ONWD | Onward Opportunities Limited | 149.3 | 148.1 | 149.3 | 11.4K | 0.3 | | 0.23 | |
| OOA | Octopus Aim Vct PLC | 43.60 | 43.60 | 45.00 | 25.6K | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 10.24 | 10.24 | 10.21 | 127 | -0.04 | | 0.43 | |
| OPG | Opg Power Ventures PLC | 5.700 | 5.300 | 5.400 | 1.25M | 0.000 | | 0.00 | |
| OPT | Optima Health PLC | 207.0 | 202.0 | 202.0 | 108.4K | -2.5 | | 1.22 | |
| OPTI | Optibiotix Health PLC | 6.500 | 6.275 | 6.290 | 311.5K | -0.160 | | 2.48 | |
| OQ12 | Standard Chartered PLC | 92.54 | 92.54 | 92.54 | 0 | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 100.1 | 100.1 | 101.2 | 0 | 0.0 | | 0.00 | |
| ORCA | Orcadian Energy PLC | 17.50 | 16.00 | 17.50 | 24.1K | 0.75 | | 4.48 | |
| ORCH | Orchard Funding Group PLC | 60.18 | 60.00 | 60.18 | 35.0K | 0.18 | | 0.29 | |
| ORCP | Oracle Power PLC | 0.1000 | 0.0650 | 0.0750 | 0 | 0.0000 | | 0.00 | |
| ORIT | Octopus Renewables Infrastructure Trust | 59.20 | 57.70 | 58.80 | 1.18M | 0.60 | | 1.03 | |
| ORNT | Orient Telecoms PLC | 3.000 | 3.000 | 4.000 | 17.3K | 0.000 | | 0.00 | |
| ORR | Oriole Resources PLC | 0.3300 | 0.3000 | 0.3300 | 23.58M | 0.0200 | | 6.45 | |
| OS73 | Toyota Finance Australia Limited | 95.90 | 95.90 | 95.90 | 0 | 0.00 | | 0.00 | |
| OSB | Osb Group PLC | 647.5 | 633.0 | 635.5 | 448.1K | -2.0 | | 0.31 | |
| OSEC | Octopus Aim Vct 2 PLC | 35.45 | 35.10 | 35.40 | 403.0K | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 58.47 | 58.39 | 58.39 | 100 | 0.18 | | 0.31 | |
| OT06 | Derwent London PLC | 72.10 | 72.10 | 72.10 | 9.6K | 0.00 | | 0.00 | |
| OT1 | Oxford Technology 2 Venture Capital | 12.00 | 12.00 | 14.50 | 70 | 0.00 | | 0.00 | |
| OT3 | Oxford Technology 2 Venture Capital | 8.500 | 8.500 | 7.500 | 10.0K | 0.000 | | 0.00 | |
| OT4 | Oxford Technology 2 Venture Capital | 7.000 | 5.000 | 5.000 | 2.5K | -2.000 | | 28.57 | |
| OTB | On The Beach Group PLC | 222.0 | 216.0 | 219.5 | 296.8K | -2.0 | | 0.90 | |
| OTES | Hellenic Telecommunications Organization | 9.440 | 9.440 | 9.440 | 8 | 0.000 | | 0.00 | |
| OTPD | Otp Bank PLC | 17.00 | 17.00 | 17.00 | 1 | 0.00 | | 0.00 | |
| OTV2 | Octopus Titan Vct PLC | 22.50 | 15.00 | 15.00 | 203.4K | -7.50 | | 33.33 | |
| OUFU | Ossiam Irl Icav | 207.1 | 207.1 | 205.2 | 3 | -1.0 | | 0.49 | |
| OVB | Ovoca Bio PLC | 1.295 | 1.045 | 1.150 | 173.3K | 0.000 | | 0.00 | |
| OVCT | Oberon Aim Vct PLC | 24.60 | 24.60 | 25.70 | 6.0K | 0.00 | | 0.00 | |
| OVZA | Wisdomtree Metal Securities Limited | 186.0 | 178.2 | 181.6 | 893 | -5.8 | | 3.08 | |
| OVZB | Wisdomtree Metal Securities Limited | 140.7 | 135.8 | 140.7 | 8.1K | -1.5 | | 1.06 | |
| OVZC | Wisdomtree Metal Securities Limited | 72.09 | 68.30 | 69.94 | 9.9K | -2.07 | | 2.87 | |
| OXA1 | Db Etc PLC | 264.8 | 261.3 | 262.1 | 2.1K | -3.2 | | 1.21 | |
| OXA2 | Db Etc PLC | 481.5 | 459.9 | 467.5 | 1.1K | -15.6 | | 3.23 | |
| OXA5 | Db Etc PLC | 380.9 | 377.7 | 379.2 | 100 | -2.1 | | 0.54 | |
| OXA6 | Db Etc PLC | 739.5 | 705.4 | 716.4 | 310 | 27.5 | | 3.98 | |
| OXB | Oxford Biomedica PLC | 952.0 | 896.0 | 899.0 | 402.9K | -14.0 | | 1.53 | |
| OXH | Oxford Technology 2 Venture Capital | 7.500 | 7.500 | 6.500 | 10.0K | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 2,415 | 2,325 | 2,410 | 134.7K | 85 | | 3.66 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |