| OAP3 | Octopus Apollo Vct PLC | 46.50 | 46.50 | 46.50 | 0 | 0.00 | | 0.00 | |
| OAUE | UBS Etf | 42.76 | 42.76 | 42.76 | 98 | 0.00 | | 0.00 | |
| OBD | Oxford Biodynamics PLC | 0.3300 | 0.3100 | 0.3250 | 13.58M | 0.0100 | | 3.17 | |
| OBI | Ondine Biomedical Inc. | 13.50 | 13.10 | 13.50 | 70.7K | 0.25 | | 1.89 | |
| OCDO | Ocado Group PLC | 232.9 | 229.6 | 231.5 | 1.37M | -0.1 | | 0.04 | |
| OCI | Oakley Capital Investments Limited | 568.0 | 556.0 | 568.0 | 338.2K | 8.0 | | 1.43 | |
| OCN | Ocean Wilsons (Holdings) LD | 1,155 | 1,130 | 1,130 | 17.0K | -10 | | 0.88 | |
| OCTF | First Trust Global Funds Public Limited | 2,061 | 2,061 | 2,061 | 0 | 9 | | 0.45 | |
| OE08 | Bank Of Montreal | 100.4 | 100.4 | 100.4 | 1.0M | 0.0 | | 0.00 | |
| OE61 | The Kingdom Of Morocco | 110.4 | 110.4 | 110.4 | 450.0K | 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 | 0 | 0.000 | | 0.00 | |
| OGG9 | Gold Bullion Securities LD | 327.0 | 311.0 | 327.0 | 8.0K | 16.1 | | 5.17 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 111.3 | 110.0 | 110.2 | 30.5K | 1.2 | | 1.09 | |
| OGN | Origin Enterprises PLC | 3.760 | 3.760 | 3.760 | 0 | 0.000 | | 0.00 | |
| OGOL | Global X Metal Securities | 54.95 | 54.95 | 54.95 | 344 | -1.05 | | 1.88 | |
| OGZU | Wisdomtree Metal Securities Limited | 331.0 | 328.1 | 328.1 | 100 | 2.5 | | 0.76 | |
| OHGR | One Health Group PLC | 239.9 | 232.0 | 239.0 | 407 | 0.0 | | 0.00 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 105.9 | 105.9 | 105.9 | 1.16M | 0.0 | | 0.00 | |
| OIG | Oryx International Growth Fund LTD | 1,330 | 1,290 | 1,330 | 8.0K | 23 | | 1.72 | |
| OIGB | Vaneck Ucits Etfs PLC | 17.26 | 16.64 | 17.16 | 2.9K | 0.61 | | 3.68 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 22.79 | 22.17 | 22.74 | 234 | 0.70 | | 3.19 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 703.8 | 680.8 | 702.0 | 244 | 22.9 | | 3.37 | |
| OIL3 | UBS AG | 84.60 | 84.60 | 84.60 | 0 | 1.07 | | 1.28 | |
| OILG | UBS AG | 7,686 | 7,686 | 7,686 | 0 | 72 | | 0.95 | |
| OILU | UBS AG | 125.8 | 125.8 | 125.8 | 0 | 1.2 | | 0.92 | |
| OIP9 | Shell International Finance B.V | 98.24 | 98.24 | 98.24 | 300.0K | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 171.9 | 167.5 | 170.0 | 176.0K | 2.8 | | 1.64 | |
| OM9S | Yorkshire Water Finance PLC | 69.60 | 69.60 | 69.60 | 100.0K | 0.00 | | 0.00 | |
| OMG | Oxford Metrics PLC | 45.30 | 43.50 | 44.50 | 172.0K | 0.50 | | 1.14 | |
| OMI | Orosur Mining INC | 22.00 | 20.00 | 21.00 | 2.17M | 1.00 | | 5.00 | |
| OMIP | One Media Ip Group PLC | 4.000 | 3.500 | 3.750 | 419 | 0.000 | | 0.00 | |
| OMU | Old Mutual Limited | 62.84 | 60.19 | 60.40 | 313.4K | -1.00 | | 1.63 | |
| OMXS | Ishares Iv PLC | 764.5 | 758.8 | 759.3 | 3.7K | 0.4 | | 0.05 | |
| ONDO | Ondo Insurtech PLC | 30.00 | 28.50 | 29.25 | 594.1K | 0.45 | | 1.56 | |
| ONT | Oxford Nanopore Technologies PLC | 138.2 | 132.7 | 138.2 | 1.52M | 3.5 | | 2.60 | |
| ONWD | Onward Opportunities Limited | 137.7 | 135.5 | 136.5 | 8.6K | -1.0 | | 0.73 | |
| OOA | Octopus Aim Vct PLC | 46.40 | 46.40 | 46.40 | 0 | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 9.824 | 9.824 | 9.824 | 4.5K | -0.077 | | 0.78 | |
| OPG | Opg Power Ventures PLC | 5.636 | 5.500 | 5.600 | 991.9K | -0.050 | | 0.88 | |
| OPT | Optima Health PLC | 200.0 | 195.0 | 197.5 | 4.08M | -1.0 | | 0.50 | |
| OPTI | Optibiotix Health PLC | 8.500 | 8.085 | 8.250 | 183.3K | 0.000 | | 0.00 | |
| OQ12 | Standard Chartered PLC | 92.69 | 92.69 | 92.69 | 1.63M | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 99.3 | 99.3 | 101.8 | 6.6K | 0.0 | | 0.00 | |
| ORCA | Orcadian Energy PLC | 15.50 | 12.80 | 15.25 | 493.6K | 2.50 | | 19.61 | |
| ORCH | Orchard Funding Group PLC | 60.00 | 58.00 | 59.00 | 377 | -1.00 | | 1.67 | |
| ORCP | Oracle Power PLC | 0.0400 | 0.0350 | 0.0380 | 63.98M | 0.0000 | | 0.00 | |
| ORIT | Octopus Renewables Infrastructure Trust | 62.80 | 61.00 | 61.00 | 1.83M | -0.30 | | 0.49 | |
| ORNT | Orient Telecoms PLC | 4.000 | 4.000 | 4.000 | 0 | 0.000 | | 0.00 | |
| ORR | Oriole Resources PLC | 0.3000 | 0.2800 | 0.2950 | 41.87M | 0.0150 | | 5.36 | |
| OS73 | Toyota Finance Australia Limited | 95.00 | 95.00 | 95.00 | 1.0M | 0.00 | | 0.00 | |
| OSB | Osb Group PLC | 550.0 | 542.0 | 544.0 | 807.5K | -2.5 | | 0.46 | |
| OSEC | Octopus Aim Vct 2 PLC | 36.40 | 36.40 | 36.40 | 0 | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 55.20 | 55.20 | 55.20 | 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 | 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 | 219.5 | 213.5 | 213.5 | 573.2K | -4.5 | | 2.06 | |
| 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 | 24.50 | 24.50 | 24.50 | 0 | 0.00 | | 0.00 | |
| OUFU | Ossiam Irl Icav | 205.6 | 205.6 | 205.6 | 0 | -0.3 | | 0.13 | |
| OVB | Ovoca Bio PLC | 1.295 | 1.045 | 1.150 | 173.3K | 0.000 | | 0.00 | |
| OVCT | Oberon Aim Vct PLC | 24.10 | 24.10 | 24.10 | 0 | 0.00 | | 0.00 | |
| OVZA | Wisdomtree Metal Securities Limited | 127.0 | 124.4 | 124.6 | 100 | 0.2 | | 0.14 | |
| OVZB | Wisdomtree Metal Securities Limited | 112.2 | 110.5 | 110.9 | 100 | 1.7 | | 1.58 | |
| OVZC | Wisdomtree Metal Securities Limited | 38.01 | 37.69 | 37.80 | 26.0K | 0.95 | | 2.58 | |
| OXA1 | Db Etc PLC | 232.1 | 230.1 | 230.1 | 100 | 1.5 | | 0.67 | |
| OXA2 | Db Etc PLC | 256.3 | 254.5 | 255.5 | 100 | 6.2 | | 2.50 | |
| OXA5 | Db Etc PLC | 332.1 | 330.0 | 330.4 | 100 | 4.5 | | 1.38 | |
| OXA6 | Db Etc PLC | 390.0 | 375.3 | 375.3 | 100 | -16.2 | | 4.15 | |
| OXB | Oxford Biomedica PLC | 663.0 | 623.0 | 654.0 | 232.5K | 14.0 | | 2.19 | |
| OXH | Oxford Technology 2 Venture Capital | 6.000 | 6.000 | 6.000 | 0 | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 1,966 | 1,904 | 1,904 | 69.4K | -30 | | 1.55 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |