Method for detecting suspicious groups in collaborative stock transactions based on bipartite graph

A method for detecting suspicious groups in collaborative stock transactions based on a bipartite graph, comprising collecting a set of suspicious accounts and a set of transaction events, the method further comprising:

• step S101) of determining whether an update occurs in the set of suspicious accounts:
• in response to that the update occurs, proceeding to step S102);
• otherwise, proceeding to step S106);
• step S102) of searching for a transaction event:
• retrieving historical stock transaction data of each suspicious account in the set of suspicious accounts to construct a transaction event, and adding the constructed transaction event to a set of candidate transaction events;
• step S103) of calculating a transaction event participation threshold:
• calculating the transaction event participation threshold based on a size of the set of transaction events, a size of the set of candidate transaction events, or iteration history;
• step S104) of updating the set of transaction events:
• calculating a participation degree of each candidate transaction event in the set of candidate transaction events, selecting a candidate transaction event having a participation degree higher than the transaction event participation threshold, and adding the candidate transaction event having the participation degree higher than the transaction event participation threshold to the set of transaction events;
• and after the addition, clearing the set of candidate transaction events;
• step S105) of determining whether the set of suspicious accounts and the set of transaction events have converged:
• determining whether elements comprised in the set of suspicious accounts and the set of transaction events are the same before and after a latest update;
• in response to that the elements comprised in the set of suspicious accounts and the set of transaction events are not the same, determining that the set of suspicious accounts and the set of transaction events have not converged, and proceeding to step S101);
• and in response to that the elements comprised in the set of suspicious accounts and the set of transaction events are the same, determining that the set of suspicious accounts and the set of transaction events have converged, and proceeding to step S109);
• step S106) of searching for a suspicious account:
• retrieving historical stock transaction data generated in each transaction event in the set of transaction events to select a stock account that has participated in at least one arbitrary transaction event in the set of transaction events, and adding the stock account selected to a set of candidate suspicious accounts;
• step S107) of calculating a suspicious account participation threshold:
• calculating the suspicious account participation threshold based on a size of the set of suspicious accounts, a size of the set of candidate suspicious accounts, or iteration history;
• step S108) of updating the set of suspicious accounts:
• calculating a participation degree of each stock account in the set of candidate suspicious accounts, selecting a stock account having a participation degree higher than the suspicious account participation threshold as a suspicious account, and adding the suspicious account selected to the set of suspicious accounts;
• and after the addition, clearing the set of candidate suspicious accounts;
• step S109) of constructing a collaborative transaction graph among accounts:
• constructing the collaborative transaction graph among accounts describing collaboration situations of all suspicious accounts on all transaction events;
• and
• step S110) of performing a group division based on the collaborative transaction graph among accounts:
• dividing the collaborative transaction graph among accounts into a plurality of account communities each having close internal collaboration based on a collaboration degree, determining the plurality of account communities each having the close internal collaboration as the suspicious groups in the collaborative stock transactions, and determining transaction events manipulated or participated by the suspicious groups as a group of transaction events;
• and outputting the suspicious groups in the collaborative stock transactions and the group of transaction events manipulated or participated by the suspicious groups, and terminating the detecting.