How much money are you moving out of the market in 3 days? If you invest your e-fund, you've lost value over the past couple of weeks. And removing it now means, especially if you've been investing over the past couple years, selling at a loss. It's better to let that money ride so it can recoup value when the markets recover, and use cash (hopefully not sitting under a mattress) to cover emergencies.

The actual ways to use cash are to find high-yield savings accounts (over the past few years some online accounts have hit 2.5-3%, though that's not common), CDs (which again you've had to go with online-only accounts to get decent returns), or some forms of bonds. These offer guaranteed returns (or at least guaranteed not to lose you anything) which is exactly what you want for your e-fund.

Absolutely invest the rest and reap the rewards (or losses, but over a couple decades should be rewards). But it's a good idea to leave the e-fund in a more stable form. Don't be like my colleague in 2008/2009 who went from being worth almost a million to being worth 200k and needing the money. He couldn't let it sit and recoup value, he just lost. His retirement was pushed out years as a result.

Admittedly, his retirement still would've been pushed 1-3 years anyways due to the financial need at the time. But he used almost half his investment's value at that point ($100k), which in a few years would've been back to $500k or so in value. If he'd even had $50k in cash (less than his annual net income), he would've only lost a quarter of his investments instead of half.