| 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 | 0.2500 | 0.2300 | 0.2400 | 9.35M | 0.0000 | | 0.00 | |
| OBI | Ondine Biomedical Inc. | 10.000 | 9.500 | 9.750 | 44.3K | 0.000 | | 0.00 | |
| OCDO | Ocado Group PLC | 240.5 | 232.1 | 240.1 | 3.61M | 5.2 | | 2.21 | |
| OCI | Oakley Capital Investments Limited | 564.0 | 556.0 | 562.0 | 443.4K | 4.0 | | 0.72 | |
| OCN | Ocean Wilsons (Holdings) LD | 1,200 | 1,175 | 1,180 | 33.8K | 0 | | 0.00 | |
| OCTF | First Trust Global Funds Public Limited | 2,018 | 2,018 | 2,018 | 0 | 0 | | 0.01 | |
| 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 | 330.4 | 330.4 | 330.4 | 3.1K | 9.2 | | 2.85 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 119.0 | 118.2 | 118.4 | 1.8K | 0.7 | | 0.58 | |
| OGN | Origin Enterprises PLC | 4.240 | 4.150 | 4.150 | 292 | 0.175 | | 4.40 | |
| OGOL | Global X Metal Securities | 59.97 | 59.97 | 59.97 | 366 | 0.71 | | 1.20 | |
| OGZU | Wisdomtree Metal Securities Limited | 353.0 | 352.7 | 353.0 | 100 | 2.6 | | 0.75 | |
| OHGR | One Health Group PLC | 252.4 | 247.8 | 251.0 | 18.1K | 0.0 | | 0.00 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 106.2 | 106.2 | 106.2 | 2.68M | 0.0 | | 0.00 | |
| OIG | Oryx International Growth Fund LTD | 1,225 | 1,209 | 1,215 | 4.1K | -5 | | 0.41 | |
| OIGB | Vaneck Ucits Etfs PLC | 17.23 | 16.90 | 16.90 | 9.2K | 0.06 | | 0.34 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 22.92 | 22.63 | 22.63 | 288 | 0.03 | | 0.11 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 608.8 | 591.8 | 597.3 | 25.5K | 18.4 | | 3.17 | |
| OIL3 | UBS AG | 79.40 | 79.40 | 79.40 | 0 | 1.16 | | 1.48 | |
| OILG | UBS AG | 7,254 | 7,254 | 7,254 | 0 | 81 | | 1.13 | |
| OILU | UBS AG | 118.8 | 118.8 | 118.8 | 0 | 1.4 | | 1.17 | |
| OIP9 | Shell International Finance B.V | 98.24 | 98.24 | 98.24 | 300.0K | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 169.0 | 163.5 | 163.5 | 108.7K | -1.5 | | 0.91 | |
| OM9S | Yorkshire Water Finance PLC | 69.60 | 69.60 | 69.60 | 100.0K | 0.00 | | 0.00 | |
| OMG | Oxford Metrics PLC | 46.80 | 45.10 | 46.40 | 75.2K | -0.10 | | 0.22 | |
| OMI | Orosur Mining INC | 22.50 | 21.00 | 22.00 | 1.21M | 0.00 | | 0.00 | |
| OMIP | One Media Ip Group PLC | 3.750 | 3.620 | 3.750 | 10.0K | 0.000 | | 0.00 | |
| OMU | Old Mutual Limited | 64.20 | 63.42 | 63.80 | 158.4K | 0.80 | | 1.27 | |
| OMXS | Ishares Iv PLC | 760.5 | 753.0 | 753.0 | 2.6K | -2.0 | | 0.26 | |
| ONDO | Ondo Insurtech PLC | 21.50 | 21.00 | 21.00 | 798.5K | 0.25 | | 1.20 | |
| ONT | Oxford Nanopore Technologies PLC | 127.3 | 122.3 | 124.7 | 1.2M | -0.9 | | 0.72 | |
| ONWD | Onward Opportunities Limited | 143.0 | 140.0 | 140.5 | 13.7K | -0.5 | | 0.35 | |
| OOA | Octopus Aim Vct PLC | 46.60 | 46.60 | 46.60 | 0 | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 9.976 | 9.933 | 9.933 | 100 | -0.004 | | 0.04 | |
| OPG | Opg Power Ventures PLC | 5.400 | 4.050 | 5.400 | 982.5K | 1.150 | | 27.06 | |
| OPT | Optima Health PLC | 194.0 | 192.0 | 192.0 | 69.7K | -1.0 | | 0.52 | |
| OPTI | Optibiotix Health PLC | 6.945 | 6.660 | 6.750 | 18.2K | 0.000 | | 0.00 | |
| OQ12 | Standard Chartered PLC | 92.46 | 92.46 | 92.46 | 0 | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 100.0 | 100.0 | 101.0 | 0 | 0.0 | | 0.00 | |
| ORCA | Orcadian Energy PLC | 13.25 | 12.50 | 13.25 | 7.9K | -0.25 | | 1.85 | |
| ORCH | Orchard Funding Group PLC | 60.49 | 60.00 | 60.00 | 19.4K | 0.00 | | 0.00 | |
| ORCP | Oracle Power PLC | 0.0400 | 0.0350 | 0.0390 | 67.15M | 0.0010 | | 2.63 | |
| ORIT | Octopus Renewables Infrastructure Trust | 60.50 | 59.10 | 59.50 | 2.56M | 0.00 | | 0.00 | |
| ORNT | Orient Telecoms PLC | 4.000 | 4.000 | 4.000 | 0 | 0.000 | | 0.00 | |
| ORR | Oriole Resources PLC | 0.2900 | 0.2600 | 0.2700 | 18.02M | -0.0100 | | 3.57 | |
| OS73 | Toyota Finance Australia Limited | 95.00 | 95.00 | 95.00 | 1.0M | 0.00 | | 0.00 | |
| OSB | Osb Group PLC | 607.5 | 598.0 | 602.5 | 467.2K | 1.5 | | 0.25 | |
| OSEC | Octopus Aim Vct 2 PLC | 35.20 | 35.20 | 35.20 | 0 | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 55.55 | 55.55 | 55.55 | 0 | 0.00 | | 0.00 | |
| 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 | 8.500 | 5.000 | 7.000 | 52.2K | 0.000 | | 0.00 | |
| OT4 | Oxford Technology 2 Venture Capital | 8.500 | 4.500 | 6.500 | 32.4K | 0.000 | | 0.00 | |
| OTB | On The Beach Group PLC | 230.0 | 225.0 | 230.0 | 223.9K | 4.5 | | 2.00 | |
| 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 | 27.00 | 23.00 | 24.50 | 75.7K | 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 | 150.9 | 146.5 | 146.5 | 100 | 2.6 | | 1.81 | |
| OVZB | Wisdomtree Metal Securities Limited | 128.3 | 125.2 | 126.1 | 195 | 0.6 | | 0.51 | |
| OVZC | Wisdomtree Metal Securities Limited | 51.42 | 50.65 | 51.03 | 3.4K | 1.88 | | 3.82 | |
| OXA1 | Db Etc PLC | 249.5 | 247.6 | 248.4 | 229 | 0.9 | | 0.37 | |
| OXA2 | Db Etc PLC | 348.0 | 344.0 | 344.1 | 100 | 9.9 | | 2.96 | |
| OXA5 | Db Etc PLC | 354.9 | 353.3 | 353.6 | 100 | 2.3 | | 0.65 | |
| OXA6 | Db Etc PLC | 527.8 | 505.7 | 505.7 | 175 | 0.5 | | 0.10 | |
| OXB | Oxford Biomedica PLC | 613.0 | 584.0 | 587.0 | 239.3K | -15.0 | | 2.49 | |
| OXH | Oxford Technology 2 Venture Capital | 7.500 | 4.000 | 6.000 | 32.0K | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 2,075 | 2,005 | 2,055 | 105.6K | 5 | | 0.24 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |