| 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 | 19 | 0.00 | | 0.00 | |
| OBD | Oxford Biodynamics PLC | 0.2200 | 0.2000 | 0.2100 | 5.56M | -0.0050 | | 2.33 | |
| OBI | Ondine Biomedical Inc | 11.00 | 10.50 | 10.75 | 107.6K | 0.00 | | 0.00 | |
| OCDO | Ocado Group PLC | 195.2 | 184.3 | 187.7 | 1.81M | -5.5 | | 2.82 | |
| OCI | Oakley Capital Investments Limited | 470.2 | 444.0 | 444.0 | 579.1K | -16.0 | | 3.48 | |
| OCTF | First Trust Global Funds Public Limited | 2,008 | 2,005 | 2,008 | 300 | 0 | | 0.00 | |
| OE08 | Bank Of Montreal | 100.4 | 100.4 | 100.4 | 1.0M | 0.0 | | 0.00 | |
| OE61 | The Kingdom Of Morocco | 106.7 | 106.7 | 106.7 | 0 | 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 | 8.200 | 8.200 | 8.200 | 120 | 0.000 | | 0.00 | |
| OGG9 | Gold Bullion Securities LD | 348.8 | 347.4 | 348.2 | 0 | -15.2 | | 4.19 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 123.1 | 120.9 | 122.7 | 2.1K | -8.7 | | 6.62 | |
| OGN | Origin Enterprises Plc | 370.0 | 355.9 | 370.0 | 600 | 366.3 | | 9900.00 | |
| OGOL | Global X Metal Securities | 56.35 | 56.35 | 56.35 | 103 | -0.87 | | 1.52 | |
| OGZU | Wisdomtree Metal Securities Limited | 365.1 | 360.8 | 360.8 | 1 | -21.8 | | 5.70 | |
| OHGR | One Health Group Plc | 242.0 | 236.6 | 241.0 | 6.9K | -2.0 | | 0.82 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 101.5 | 101.5 | 101.5 | 0 | -2.8 | | 2.68 | |
| OIG | Oryx International Growth Fund Ltd | 1,240 | 1,155 | 1,185 | 20.8K | 10 | | 0.85 | |
| OIGB | Vaneck Ucits Etfs PLC | 25.19 | 24.32 | 25.14 | 22.5K | 0.94 | | 3.86 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 33.69 | 32.66 | 33.51 | 102.0K | 0.96 | | 2.95 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 1,579 | 1,485 | 1,577 | 805 | 13 | | 0.85 | |
| OIL3 | UBS AG | 112.2 | 109.7 | 126.1 | 128 | -9.5 | | 6.97 | |
| OILG | UBS AG | 7,466 | 7,466 | 10,408 | 0 | 0 | | 0.00 | |
| OILU | UBS AG | 164.9 | 161.3 | 168.6 | 315 | -4.6 | | 2.61 | |
| OIP9 | Shell International Finance B.V | 97.70 | 97.70 | 97.70 | 0 | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 178.7 | 173.0 | 175.0 | 561.3K | 0.0 | | 0.00 | |
| OM9S | Yorkshire Water Finance PLC | 77.48 | 77.48 | 77.48 | 0 | -1.11 | | 1.41 | |
| OMG | Oxford Metrics plc | 44.60 | 43.86 | 44.00 | 75.3K | 0.20 | | 0.46 | |
| OMI | Orosur Mining Inc | 18.00 | 17.08 | 18.00 | 973.5K | 0.00 | | 0.00 | |
| OMIP | One Media iP Group Plc | 3.350 | 3.100 | 3.350 | 375.0K | 0.000 | | 0.00 | |
| OMU | Old Mutual Ltd | 61.60 | 58.00 | 58.00 | 177.9K | -2.80 | | 4.61 | |
| OMXS | Ishares Iv PLC | 757.8 | 750.3 | 756.8 | 16.7K | 2.0 | | 0.26 | |
| ONDO | Ondo InsurTech PLC | 15.00 | 14.51 | 14.65 | 269.5K | -0.25 | | 1.68 | |
| ONT | Oxford Nanopore Technologies Ltd | 118.6 | 112.4 | 116.8 | 1.2M | 1.5 | | 1.30 | |
| ONWD | Onward Opportunities Limited | 126.5 | 122.1 | 124.5 | 20.9K | -4.8 | | 3.71 | |
| OOA | Octopus Aim Vct Plc | 38.60 | 38.60 | 38.60 | 0 | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 9.835 | 9.820 | 9.835 | 7 | 0.073 | | 0.75 | |
| OPT | Optima Health Plc | 182.0 | 178.0 | 180.0 | 55.6K | -0.4 | | 0.22 | |
| OPTI | OptiBiotix Health Plc | 5.500 | 5.000 | 5.250 | 829.5K | 0.000 | | 0.00 | |
| OQ12 | Standard Chartered PLC | 91.00 | 91.00 | 91.00 | 0 | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 103.0 | 103.0 | 100.5 | 0 | 2.2 | | 2.21 | |
| ORCA | Orcadian Energy PLC | 14.70 | 14.00 | 14.50 | 231.4K | 0.25 | | 1.75 | |
| ORCH | Orchard Funding Group Plc | 57.00 | 54.67 | 56.00 | 10.4K | -1.00 | | 1.75 | |
| ORCP | Oracle Coalfields Plc | 0.0450 | 0.0385 | 0.0425 | 40.81M | 0.0035 | | 8.97 | |
| ORIT | Octopus Renewables Infrastructure Trust | 59.00 | 56.80 | 57.80 | 1.31M | -0.30 | | 0.52 | |
| ORNT | Orient Telecoms Plc | 4.000 | 4.000 | 4.000 | 0 | 0.000 | | 0.00 | |
| ORR | Oriole Resources PLC | 0.3000 | 0.2800 | 0.2900 | 15.29M | 0.0000 | | 0.00 | |
| OS73 | Toyota Finance Australia Limited | 96.04 | 96.04 | 96.04 | 0 | 0.00 | | 0.00 | |
| OSB | OneSavings Bank PLC | 547.0 | 536.0 | 538.0 | 660.6K | -0.5 | | 0.09 | |
| OSEC | Octopus Aim Vct 2 Plc | 30.80 | 30.80 | 30.80 | 0 | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 54.61 | 53.91 | 53.91 | 736 | 1.50 | | 2.86 | |
| 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 | 7.500 | 7.500 | 7.500 | 0 | 0.000 | | 0.00 | |
| OT4 | Oxford Technology 2 Venture Capital | 7.500 | 7.500 | 7.500 | 0 | 0.000 | | 0.00 | |
| OTB | On The Beach Group PLC | 168.5 | 162.0 | 163.8 | 475.8K | -3.2 | | 1.92 | |
| OTES | Hellenic Telecommunications Organization | 9.600 | 9.600 | 9.600 | 0 | -0.090 | | 0.94 | |
| OTPD | Otp Bank PLC | 17.00 | 17.00 | 17.00 | 1 | 0.00 | | 0.00 | |
| OTV2 | Octopus Titan Vct Plc | 21.50 | 21.50 | 21.50 | 0 | 0.00 | | 0.00 | |
| OVB | Ovoca Bio PLC | 7.920 | 7.000 | 7.300 | 513.9K | 0.000 | | 0.00 | |
| OVCT | Oberon Aim Vct Plc | 25.70 | 25.70 | 25.70 | 0 | 0.00 | | 0.00 | |
| OVZA | Wisdomtree Metal Securities Limited | 150.4 | 147.1 | 150.3 | 107 | 0.0 | | 0.03 | |
| OVZB | Wisdomtree Metal Securities Limited | 113.0 | 109.8 | 111.8 | 4 | 0.5 | | 0.46 | |
| OVZC | Wisdomtree Metal Securities Limited | 55.26 | 53.45 | 55.05 | 6.8K | -11.36 | | 17.11 | |
| OXA1 | Db Etc PLC | 251.8 | 248.2 | 250.9 | 2.0K | -16.0 | | 6.01 | |
| OXA2 | Db Etc PLC | 365.0 | 354.6 | 363.4 | 581 | 8.3 | | 2.34 | |
| OXA5 | Db Etc PLC | 366.1 | 362.1 | 366.1 | 11 | -16.5 | | 4.30 | |
| OXA6 | Db Etc PLC | 565.5 | 548.8 | 564.2 | 57 | -21.0 | | 3.58 | |
| OXB | Oxford BioMedica PLC | 607.9 | 589.0 | 593.0 | 178.3K | -9.0 | | 1.50 | |
| OXH | Oxford Technology 2 Venture Capital | 7.000 | 7.000 | 7.000 | 0 | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 2,555 | 2,410 | 2,460 | 282.7K | 20 | | 0.82 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |