Zuma denies the charges of money-laundering, corruption, fraud and racketeering but says he will step down if convicted.
A long trial might mean Zuma’s legal battle overlaps with a general election in 2009, which he would almost certainly win, and the combination could increase political instability in Africa’s biggest economy.
While the uncertainty makes investors uncomfortable, they expect the case to drag on and are more focused on the impact of global market turmoil, said Razia Khan, regional head of research for Africa at Standard Chartered.
"This issue is not at the forefront. The uncertainty has gone on for some time," she said.
Even if Zuma fails to have the charges dismissed, a trial might be delayed for months, even years, because he would be able to turn to the appeals court and then South Africa’s highest court, the Constitutional Court.
Asked if prosecutors will still pursue the case if Zuma is cleared on Friday, spokesman Tlali Tlali said: "Lets’s talk about it after the judgement."
ANC spokeswoman Jessie Duarte said Zuma would not give up if his application is rejected.
"We as the ANC will apply for a permanent stay of prosecution. We have already begun the process of seeking legal council," she said.
"The continuous adding of charges implies malicious intent on the part of the NPA (prosecutors)."
The case has stirred passions among Zuma’s powerful supporters in trade unions, an alliance that has worried investors who want assurances he will not stray from Mbeki’s business-friendly policies.
Emotions have been running high in the build-up to Zuma’s court appearance on Friday, when thousands of supporters are expected to show up. About three hundred gathered and sang songs backing Zuma before the court session began.
A pro-Zuma march turned violent in the port of Durban on Wednesday. Stones were hurled at police and vehicles damaged.
There was outrage this week when a newspaper published a cartoon of Zuma undoing his trousers and appearing to be ready to rape a woman, who represented the justice system. Zuma was acquitted of rape in 2006.
The charismatic politician’s supporters say he is the victim of a political witch-hunt by backers of his rival Mbeki.
Zuma is accused of taking 783 bribes totalling 4.07 million rand over a 10-year period.
He is also accused of soliciting a 500,000 rand bribe from French arms group Thint relating to an arms deal arranged by South Africa in the late 1990s.
But Zuma has made a remarkable comeback despite the damage to his image. He has been more decisive than Mbeki on the post-election turmoil in Zimbabwe. He has stayed close to unions, promised to help the poor and courted foreign investors.