| OAP3 | Octopus Apollo Vct PLC | 46.30 | 46.30 | 46.30 | 0 | 0.00 | | 0.00 | |
| OAUE | UBS Etf | 42.76 | 42.76 | 42.76 | 11 | 0.00 | | 0.00 | |
| OBD | Oxford Biodynamics PLC | 0.2700 | 0.2500 | 0.2600 | 23.03M | 0.0010 | | 0.39 | |
| OBI | Ondine Biomedical Inc. | 11.50 | 11.00 | 11.25 | 127.9K | -0.05 | | 0.44 | |
| OCDO | Ocado Group PLC | 190.1 | 183.0 | 188.5 | 2.41M | 3.8 | | 2.03 | |
| OCI | Oakley Capital Investments Limited | 576.0 | 548.0 | 564.0 | 353.2K | 14.0 | | 2.55 | |
| OCN | Ocean Wilsons (Holdings) LD | 1,200 | 1,175 | 1,180 | 33.8K | 0 | | 0.00 | |
| OCTF | First Trust Global Funds Public Limited | 2,045 | 2,045 | 2,045 | 0 | -4 | | 0.17 | |
| OE08 | Bank Of Montreal | 100.4 | 100.4 | 100.4 | 1.0M | 0.0 | | 0.00 | |
| OE61 | The Kingdom Of Morocco | 108.4 | 108.4 | 108.4 | 1.47M | 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 | 0 | 0.000 | | 0.00 | |
| OGG9 | Gold Bullion Securities LD | 330.2 | 330.2 | 330.2 | 145 | 0.0 | | 0.00 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 116.4 | 115.5 | 116.1 | 1.8K | -0.5 | | 0.44 | |
| OGN | Origin Enterprises PLC | 3.900 | 3.880 | 3.900 | 250 | 0.000 | | 0.00 | |
| OGOL | Global X Metal Securities | 58.03 | 58.03 | 58.03 | 100 | 1.68 | | 2.98 | |
| OGZU | Wisdomtree Metal Securities Limited | 346.0 | 345.2 | 345.2 | 0 | -4.5 | | 1.29 | |
| OHGR | One Health Group PLC | 256.0 | 247.5 | 251.0 | 108.8K | 1.9 | | 0.77 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 106.2 | 106.2 | 106.2 | 2.68M | 0.0 | | 0.00 | |
| OIG | Oryx International Growth Fund LTD | 1,226 | 1,205 | 1,205 | 5.1K | -6 | | 0.45 | |
| OIGB | Vaneck Ucits Etfs PLC | 18.46 | 18.11 | 18.17 | 1.2K | -0.36 | | 1.92 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 24.70 | 24.19 | 24.22 | 9.7K | -0.48 | | 1.92 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 677.8 | 662.6 | 662.6 | 16.7K | -20.9 | | 3.05 | |
| OIL3 | UBS AG | 83.05 | 83.05 | 83.05 | 0 | -1.23 | | 1.46 | |
| OILG | UBS AG | 7,516 | 7,516 | 7,516 | 0 | -96 | | 1.26 | |
| OILU | UBS AG | 123.1 | 123.1 | 123.1 | 0 | -1.6 | | 1.26 | |
| OIP9 | Shell International Finance B.V | 98.24 | 98.24 | 98.24 | 300.0K | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 171.5 | 167.0 | 167.0 | 151.5K | 0.0 | | 0.00 | |
| OM9S | Yorkshire Water Finance PLC | 69.60 | 69.60 | 69.60 | 100.0K | 0.00 | | 0.00 | |
| OMG | Oxford Metrics PLC | 44.00 | 41.50 | 42.50 | 669.9K | 0.53 | | 1.27 | |
| OMI | Orosur Mining INC | 24.50 | 23.00 | 23.50 | 2.52M | 0.73 | | 3.21 | |
| OMIP | One Media Ip Group PLC | 3.810 | 3.688 | 3.750 | 42.0K | 0.000 | | 0.00 | |
| OMU | Old Mutual Limited | 62.40 | 60.60 | 61.00 | 76.2K | 0.00 | | 0.00 | |
| OMXS | Ishares Iv PLC | 760.5 | 754.8 | 754.8 | 10.1K | -5.6 | | 0.74 | |
| ONDO | Ondo Insurtech PLC | 23.50 | 22.50 | 22.80 | 1.7M | -0.70 | | 2.98 | |
| ONT | Oxford Nanopore Technologies PLC | 132.4 | 124.8 | 130.5 | 2.03M | 2.9 | | 2.27 | |
| ONWD | Onward Opportunities Limited | 138.0 | 136.6 | 138.0 | 1.4K | -1.2 | | 0.86 | |
| OOA | Octopus Aim Vct PLC | 45.60 | 45.60 | 45.60 | 0 | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 9.870 | 9.800 | 9.800 | 100 | -0.081 | | 0.82 | |
| OPG | Opg Power Ventures PLC | 5.600 | 5.326 | 5.400 | 6.39M | 0.000 | | 0.00 | |
| OPT | Optima Health PLC | 195.0 | 193.0 | 194.0 | 461.3K | 1.0 | | 0.52 | |
| OPTI | Optibiotix Health PLC | 8.000 | 7.163 | 7.250 | 525.4K | -0.469 | | 6.08 | |
| OQ12 | Standard Chartered PLC | 92.47 | 92.47 | 92.47 | 450.0K | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 100.0 | 100.0 | 101.1 | 0 | 0.0 | | 0.00 | |
| ORCA | Orcadian Energy PLC | 14.50 | 12.50 | 13.50 | 12.6K | -0.48 | | 3.43 | |
| ORCH | Orchard Funding Group PLC | 60.00 | 57.00 | 59.50 | 18.4K | -0.38 | | 0.63 | |
| ORCP | Oracle Power PLC | 0.0400 | 0.0330 | 0.0350 | 120.12M | -0.0050 | | 12.50 | |
| ORIT | Octopus Renewables Infrastructure Trust | 60.00 | 59.00 | 59.40 | 1.69M | -0.60 | | 1.00 | |
| ORNT | Orient Telecoms PLC | 4.000 | 4.000 | 4.000 | 0 | -0.500 | | 11.11 | |
| ORR | Oriole Resources PLC | 0.2900 | 0.2600 | 0.2750 | 16.53M | 0.0060 | | 2.23 | |
| OS73 | Toyota Finance Australia Limited | 95.00 | 95.00 | 95.00 | 1.0M | 0.00 | | 0.00 | |
| OSB | Osb Group PLC | 581.5 | 563.5 | 570.5 | 353.3K | 2.9 | | 0.51 | |
| OSEC | Octopus Aim Vct 2 PLC | 34.20 | 34.20 | 34.20 | 0 | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 55.82 | 55.75 | 55.82 | 0 | -0.10 | | 0.18 | |
| OT06 | Derwent London PLC | 72.10 | 72.10 | 72.10 | 9.6K | 0.00 | | 0.00 | |
| OT1 | Oxford Technology 2 Venture Capital | 14.50 | 14.50 | 14.50 | 0 | 0.00 | | 0.00 | |
| OT3 | Oxford Technology 2 Venture Capital | 7.000 | 7.000 | 7.000 | 0 | 0.000 | | 0.00 | |
| OT4 | Oxford Technology 2 Venture Capital | 6.500 | 6.500 | 6.500 | 0 | 0.000 | | 0.00 | |
| OTB | On The Beach Group PLC | 226.5 | 215.0 | 223.5 | 813.9K | 8.1 | | 3.74 | |
| 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 | 0 | 0.00 | | 0.00 | |
| OTV2 | Octopus Titan Vct PLC | 26.00 | 24.50 | 24.50 | 100.0K | 0.00 | | 0.00 | |
| 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 | 25.30 | 25.30 | 25.30 | 0 | 0.00 | | 0.00 | |
| OVZA | Wisdomtree Metal Securities Limited | 130.6 | 129.6 | 129.8 | 100 | -0.1 | | 0.11 | |
| OVZB | Wisdomtree Metal Securities Limited | 116.3 | 115.1 | 115.4 | 100 | 0.4 | | 0.34 | |
| OVZC | Wisdomtree Metal Securities Limited | 45.83 | 45.30 | 45.30 | 1.9K | -0.57 | | 1.24 | |
| OXA1 | Db Etc PLC | 242.0 | 240.3 | 240.3 | 0 | -2.9 | | 1.21 | |
| OXA2 | Db Etc PLC | 308.7 | 304.4 | 306.0 | 100 | -5.2 | | 1.66 | |
| OXA5 | Db Etc PLC | 347.0 | 345.0 | 345.1 | 100 | -2.0 | | 0.59 | |
| OXA6 | Db Etc PLC | 470.4 | 460.3 | 460.3 | 100 | -9.5 | | 2.01 | |
| OXB | Oxford Biomedica PLC | 646.0 | 613.0 | 644.0 | 168.6K | 25.2 | | 4.07 | |
| OXH | Oxford Technology 2 Venture Capital | 6.000 | 6.000 | 6.000 | 0 | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 2,195 | 2,075 | 2,075 | 179.9K | -75 | | 3.49 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |